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From Other Journals

By Journal Review Editors
Richard Ohye, MD
David G. Thoele, MD

Past Editor: Scott M. Bradley, MD

These are article reviews published in Pediatric Cardiology.  The reviews are of articles published in pediatric and cardiology journals.

 

From Other Journals/Pediatric Cardiology

Contents

2001 Issues:
May/June 2001 issue [22.3]
July/August 2001 issue [22.4]
September/October 2001 issue [22.5]

November/December 2001 issue [22.6]

2002 Issues:
January/February 2002 issue [23.1]
March/April 2002 issue [23.2]
May/June 2002 issue [23.3]
July/August 2002 issue [23.4]
September/October 2002 issue [23.5]
November/December 2002 issue [23.6]

2003 Issues:
January/February 2003 issue [24.1]
March/April 2003 issue [24.2]
May/June 2003 issue [24.3]
September/October 2003 issue [24.5]

2004 Issues:
January/February 2004 issue [25.1]
March/April 2004 issue [25.2]
May/June 2004 issue [25.3]
July/August 2004 issue [25.4]



2001 Issues:

From Other Journals/Pediatric Cardiology 22.3 (May/June 2001)

 

Lofland GK, McCrindle BW, Williams WG, Blackstone EH, Tchervenkov CI, Sittiwangkul R, Jonas RA, Congenital Heart Surgeons Society.

Critical aortic stenosis in the neonate: a multi-institutional study of management, outcomes, and risk factors.

J Thorac Cardiovasc Surg 2001; 121:10-27.

 From 1994 to 2000, 320 neonates with critical aortic stenosis were entered into this prospective, multi-institutional study. Patient management was determined by the individual institutions. An initial Norwood procedure was used in 179 patients, with a 5-year survival of 60%. An initial biventricular repair was pursued in 116 patients (including a transcatheter balloon valvotomy in 83, and surgical aortic valvotomy in 28), with a 5-year survival of 70%. Separate multivariable hazard models for the 2 pathways were constructed and used to predict which of the 2 pathways would have resulted in better survival for each of the patients. Factors associated with better survival for a Norwood procedure compared to a biventricular repair were younger age, smaller size of the aorta at the sinuses of Valsalva, lower left ventricular length, higher grade of endocardial fibroelastosis, less severe tricuspid regurgitation, and larger size of the ascending aorta. Predicted survival benefit favored a Norwood procedure in 50% of the patients who actually underwent biventricular repair, and favored a biventricular repair in 20% of the patients who actually underwent a Norwood procedure.

 ¨            Several previous studies have examined risk factors for mortality in neonates with critical aortic stenosis. This study is notable for its large patient cohort, prospective approach, current treatment era, and inclusion of all variables examined in previous studies. It demonstrates that mortality remains high for critical aortic stenosis in neonates, and that many patients are assigned to a pathway which probably does not optimize their survival. The study is limited by the lack of information on other treatment pathways, such as cardiac transplantation, and the Ross procedure. The multivariable equation and calculator derived in this study are posted on the Web site of the CHSS and can be prospectively used to determine management in neonates with critical aortic stenosis.

  

Shaddy RE, Lambert LM, Fuller TC, Profaizer T, Thompson DD, Baker SI, Osborne KA, Hawkins JA.

Prospective randomized trial of azathioprine in cryopreserved valved allografts in children.

Ann Thorac Surg 2001; 71:43-8.

 20 children were prospectively randomized to receive either azathioprine, or no azathioprine after receiving a cryopreserved valved allograft in the pulmonary position. 12 other patients were approached for inclusion in the study, but refused enrollment. Seven of the 20 patients withdrew before completion of the study. Four patients in the azathioprine group withdrew: 1 due to perioperative death, 1 to avoid further blood draws, 1 due to bacteremia, and 1 due to clostridium difficile colitis. 3 patients in the control group withdrew: 1 due to perioperative death, 1 to avoid further blood draws, and 1 due to mediastinitis. Thus 13 patients completed the study, 6 azathioprine and 7 controls. Panel reactive antibodies 3 months after operation rose from 0% to 84% in azathioprine patients, and from 1% to 96% in control patients (no significant difference between the 2 groups). There were also no differences between the 2 groups in allograft stenosis or regurgitation measured by echocardiography 13-17 months after operation.

 ¨         The role of immunologic rejection in limiting the durability of cryopreserved allografts remains controversial. This study is unique because it examines the effects of azathioprine on humoral immune response and allograft function in children in a prospective, randomized fashion. The small number of patients to complete the protocol underscores the many difficulties of  pursuing such a study. The study bears out previous studies by this and other groups demonstrating a  significant humoral immune response in the majority of children receiving cryopreserved allografts. The authors found that azathioprine had no important effect on this immune response, nor on allograft function. This leaves open the question of whether other, more potent immunosuppression drugs would be more effective, although it seems likely that their side effects would outweigh their potential benefits.

  

Mahle WT, Spray TL, Gaynor W, Clark BJ III.

Unexpected death after reconstructive surgery for hypoplastic left heart syndrome.

Ann Thorac Surg 2001; 71:61-65.

 The incidence of unexpected death was determined retrospectively among 536 patients with hypoplastic left heart syndrome who were discharged from the hospital after stage I surgery (Norwood procedure). These patients’ operations spanned a 15-year period, from 1984 to 1999. Unexpected death (defined as cardiovascular collapse from which the subject did not regain consciousness) occurred in 22 of 536 patients (4.1%). In addition, “nonoperative deaths” occurred in 63 of 536 patients (11.8%). The median age at unexpected death was 79 days (range 25-227 days); the median time from discharge to death was 40 days (range 1-208 days). Autopsy in 12 patients identified residual lesions in 2 patients, shunt narrowing in one and aortic coarctation in the other. Multivariable analysis showed that perioperative arrhythmia and earlier year of operation were associated with unexpected death.

 ¨               Interstage, nonoperative mortality has been observed in all series of staged surgical palliation for hypoplastic left heart syndrome. Most such deaths occur following discharge after Norwood procedure and prior to second stage, superior cavopulmonary connection. This retrospective study documents the incidence of unexpected death in a large series over a 15-year period. Possible causes of such mortality may include aortic arch obstruction, shunt thrombosis, arrhythmias, neurodevelopmental impairment with feeding difficulties and aspiration, and impaired coronary perfusion with ventricular dysfunction. However, in the majority of cases the specific cause is unknown. There remains much room for further study of the causes of interstage mortality in patients with hypoplastic left heart syndrome.

 

Schreiber C, Eicken A, Vogt M, Gunther T, Wottke M, Thielman M, Paek SU, Meisner H, Hess J, Lange R.

Repair of interrupted aortic arch: results after more than 20 years.

Ann Thorac Surg 2000; 70:1986-1900.

 Between 1975 and 1999, 94 patients underwent surgery for interrupted aortic arch. A single-stage operation was performed in 75 (80%), and two-stage in 19 (20%). Mean follow-up was 6.7 years (range 0.1-21 years). For the single-stage approach, early mortality was 12% and late mortality 20%. For the two-stage approach, early mortality was 37% and late mortality 26%. Only 9 of the 19 two-stage patients attained complete repair. Left ventricular outflow tract obstruction (defined as a ratio of the diameter of the outflow tract to the diameter of the descending aorta of 0.6 or less) was seen in 13% of patients and was a risk factor for overall mortality. Freedom from reoperation at 5 years was 67%, and at 10 years was 53%. Reintervention was most commonly for aortic arch obstruction, airway compression, and left ventricular outflow tract obstruction.

 ¨               This large series of infants with interrupted aortic arch supports the surgical approach of single-stage repair. Nonetheless, both mortality and late reintervention remain significant. In this series, left ventricular outflow tract obstruction was associated with both mortality and the need for reintervention. The exact degree of outflow tract obstruction which mandates surgical relief at the first operation, as well as  the best surgical approach to such relief, remain open questions.

  

Stamm C, Friehs I, Mayer JE Jr., Zurakowski D, Triedman JK, Moran AM, Walsh EP, Lock JE, Jonas RA, del Nido PJ.

Long-term results of the lateral tunnel Fontan operation.

J Thorac Cardiovasc Surg 2001; 121:28-41.

 From October 1987 to December 1991, 220 patients underwent an intra-atrial, lateral tunnel Fontan procedure at Children’s Hospital Boston. Median patient age was 3.9 years; 38 (17%) had undergone a prior bidirectional Glenn shunt; 140 (63%) of the Fontan procedures were fenestrated. Operative failure (death or Fontan takedown) was 6%; risk factors were higher pulmonary vascular resistance, pulmonary artery distortion, higher postoperative Fontan pressure, and a single right ventricle. 33 patients (15%) had pleural effusions lasting more than 2 weeks. Follow-up was available for 196 patients (94%) at a mean of 10.2 years. Freedom from failure (death or takedown) at 10 years was 87%; the only risk factor was previous coarctation repair. Freedom from new supraventricular tachyarrhythmia (SVT) at 10 years was 91%; risk factors for late SVT were a common atrioventricular valve or atrioventricular valve regurgitation, early postoperative supraventricular tachycardia, and preoperative bradyarrhythmia. Freedom from new bradyarrhythmia at 10 years was 79%; the most important risk factors were preoperative bradyarrhythmia and early postoperative bradyarrhythmia. Only 3 patients developed protein-losing enteropathy.

 ¨         The two most commonly used approaches to Fontan’s operation are currently the intra-atrial lateral tunnel, and the extracardiac conduit. This report provides important long-term information on a large group of patients who underwent a lateral tunnel Fontan procedure at a single institution. It demonstrates that this technical approach to the Fontan operation can result in good long-term survival with low incidences of failure and SVT. Sinus node dysfunction remains an important issue. It is of interest that baffle fenestration did not affect either early or late outcome in this group of patients. As with many congenital heart operations, the Fontan procedure constitutes a moving target. It is possible that more recent changes, such as routine staging with a prior superior cavopulmonary connection, might affect (?improve) results even further. Nonetheless, this report provides a good benchmark for comparison to other approaches, such as the extracardiac conduit Fontan.

  

Ing FF, Fagan TE, Grifka RG, Clapp S, Nihill MR, Cocalis M, Perry J, Mathewson J, Mullins CE.  Reconstruction of stenotic or occluded iliofemoral veins and inferior vena cava using intravascular stents: Re-establishing access for future cardiac catheterization and cardiac surgery.  J Am Coll Cardiol 2001;37:251-257.

 24 patients (range 0.2 to 12 years) underwent stent reconstruction of stenotic or occluded iliofemoral veins (IFV) and inferior vena cava (IVC).  85 stents were placed in 22 IFV and 6 IVC; 15 vessels were severely stenotic and 3 were completely occluded.  Occluded vessels required puncture through the thrombosed sites using a stiff wire or transseptal needle, followed by serial dilation and then stent implantation.  Vessel diameter increased from 0.9 mm to 7.4 mm.  Follow-up study of 15 stented vessels showed 13 (85%) were patent.

 ·                 In recent years, there has been increased success in treating patients with complex congenital heart disease, sometimes requiring repeated cardiac catheterizations and surgeries.  Because of the need for repeated vascular access, vessel occlusion (that may occur as a result of these procedures) can be a significant problem in managing these patients.  This excellent study offers an important technique for reconstructing stenotic or occluded veins.  I found the detailed description of the procedures (including specifics of equipment used, helpful tips, and multiple photographs) very helpful.  Highly recommended for anyone who has encountered this problem in the cath lab or surgical suite.

 

 Ovadia M, Cooper RS, Parnell VA, Dicapua D, Vatsia SK, Vlay SC.  Transvenous pacemaker insertion ipsilateral to chronic subclavian vein obstruction: An operative technique for children and adults.  PACE 2000;23:1585-1593.

The authors describe an operative technique to provide ipsilateral access in chronic subclavian vein occlusion in 5 consecutive pediatric (4 children, age 3-9) and adult (one, age 70) patients in order to insert pacing electrodes.  Indications for pacing were complete heart block in children and ventricular tachycardia in the adult.  Percutaneous brachiocephalic or deep subclavian access was achieved by a supraclavicular approach.  Electrodes were positioned in the heart and tunneled to a pre- or retropectoral pocket.  Pacemaker and implantable cardioverter defibrillator (ICD) implants were successful in all, without complication.

 ·                 The authors describe what appears to be a powerful new technique for patients with subclavian venous occlusion who require a pacemaker or ICD placement.  Using this method may avoid use of the contralateral vein, so that the chance of bilateral obstruction is minimized.  Because of increased problems with vessel occlusion in patients requiring multiple procedures (see previous article and comments), new approaches for addressing this challenge are welcome.

 

 Hernandez-Diaz S, Werler MM, Walker AM, Mitchell AA.  Folic acid antagonists during pregnancy and the risk of birth defects.  N Engl J Med 2000;343:1608-1614.

 Periconceptional use of multivitamins may reduce the risk of cardiovascular defects and other congenital malformations in offspring.  In order to determine whether the folic acid component of multivitamins helps reduce these defects, the authors examined the associations between maternal use of folic acid antagonists, antiepileptic medications, and congenital malformations, using interviews with mothers of infants with malformations in 80 maternity or tertiary care hospitals, over a 24 year period. The exposure to these medications was assessed in 3870 infants with cardiovascular defects, 1962 with oral clefts, 1100 with urinary tract defects, and in 8387 controls (infants with malformations not influenced by vitamin supplementation).  Among mothers exposed to the folic acid antagonists, the relative risk of cardiovascular defects was 3.4, while the risk of oral clefts was 2.6.  Mothers exposed to antiepileptic medications had relative risks of 2.2 (cardiovascular defects), 2.5 (oral clefts), and 2.5 (urinary tract defects).  Use of multivitamins containing folic acid diminished the adverse effects of folic acid antagonists, but not that of antiepileptic drugs.

 ·                 This interesting, large study strongly suggests that maternal use of multiple vitamins containing folic acid may reduce the incidence of congenital heart disease in the offspring of these pregnancies.  While I have sometimes joked with my adult cardiology colleagues that they could be put out of business with a few vitamin pills and lifestyle changes, it also appears that vitamins could also cut down on our patient population.  This would obviously be beneficial for the children and families who would avoid echoes, surgeries, and catheterizations, but if the benefits of prevention become too widespread, we pediatric cardiologists might also face a diminished workload (you can decide for yourself if this would be good or bad for you).

 

 Fredriksen PM, Chen A, Veldtman G, Hechter S, Therrien J, Webb G.  Exercise capacity in adult patients with congenitally corrected transposition of the great arteries.  Heart 2001;85:191-195.

 41 adults with congenitally corrected transposition of the great arteries (CCTGA) had cardiopulmonary testing at rest and with exercise.  Aerobic capacity (V02max) was diminished at 30-50% of that found in normal subjects.  Although RV and LV ejection fractions (EF) were normal at rest, with exercise, the EF of the systemic RV only increased 2% (vs. > 5% in healthy subjects), while the EF decreased by 2% in the pulmonary LV.  Other factors that may have contributed to decreased exercise capacity include blunted peak heart rate and systolic blood pressure with exercise, decreased forced expiratory volume in one second (FEV1), and decreased forced vital capacity.

 ·                 Patients with CCTGA have increasing morbidity and mortality as they age; this study provides useful information why this is so.

 

 Van Overmeire B, Van de Broek H, Van Laer P, Weyler J, Vanhaesebrouck P.  Early versus late indomethacin treatment for patent ductus arteriosus in premature infants with respiratory distress syndrome.  J Pediatr 2001;138:205-211.

 127 premature infants (gestational age 26-31 weeks) with PDA were randomly assigned to receive early (day 3) or late (day 7) intravenous indomethacin.  Although the PDA closure rate was higher in the early group at 6 days (73% vs. 44%) and 9 days of age (91% vs. 78%), there was no difference in subsequent need for PDA ligation.  The early treatment group had lower urine output, higher serum creatinine, more indomethacin courses, and more major adverse events (death, necrotizing enterocolitis, extension of hemorrhage, cystic leukomalacia).

 ·                 This large, prospective, multicenter trial appears to show minimal benefits and significant morbidity with early administration of indomethicin in premature neonates with a PDA.  Although older studies suggested a benefit for early treatment, these were done prior to recent advances in care such as antenatal corticosteroids and early treatment with surfactant.

 

 Brembilla-Perrot B, Marçon F, Bosser G, Lucron H, Houriez P, Claudon O, Holban I, Blangy H.  Paroxysmal tachycardia in children and teenagers with normal sinus rhythm and without heart disease.  PACE 2001;24:41-45.

 31 children or adolescents (age 9-19) with normal ECG and suspected or documented episodes of supraventricular tachycardia (with palpitations and syncope) had esophageal programmed stimulation.  Sustained tachycardia was induced in 27 patients, at rest in 13, and after isoproterenol in 14.  AV nodal reentrant tachycardia was the cause in 22 of these.  6 patients had a vagal reaction and dizziness.

 ·                 As the authors suggest, the diagnosis of supraventricular tachycardia could be underestimated in adolescents whose symptoms are dismissed because noninvasive studies are negative.  If symptoms suggest possible supraventricular tachycardia, esophageal or traditional electrophysiology studies should probably be considered.

 


From Other Journals/Pediatric Cardiology 22.4 (July/August 2001)

 

Dilated cardiomyopathy in isolated congenital complete atrioventricular block: Early and long-term risk in children.  Udink ten Cate FEA, Breur JMPJ, Cohen MI, Boramanand N, Kapusta L, Crosson JE, Brenner JI, Lubbers LJ, Friedman AH, Vetter VL, Meijboom EJ. J Am Coll Cardiol 2001; 37:1129-1134.

 To identify the risk factors predicting development of dilated cardiomyopathy (DCM) in patients with isolated congenital complete atrioventricular block (CCAVB), 149 patients with CCAVB were retrospectively evaluated, with a mean follow-up of 10 years.  9 patients developed DCM at age 6.5 ± 5 years.  8/9 had pacemakers in the first month of life.  In patients who developed DCM, the initial left ventricular end-diastolic dimension (LVEDD) was in the 96th percentile and the cardiothoracic (CT) ratio was 64%; this was significantly higher than patients who did not develop DCM.  After initiating pacing, LVEDD and CT ratio decreased significantly in patients without DCM, but did not improve in patients with DCM.  Among patients with DCM, two died, one is neurologically compromised, two had heart transplantation, and four are listed for heart transplantation.

 ·                 Patients with CCAVB have traditionally been considered relatively benign, though patients eventually require pacemakers.  This large, multicenter study suggests that a significant subset of these patients are at risk for developing DCM despite pacemaker placement, and such patients may require more intensive therapy.

 

 Cardiac output and central distribution of blood flow in the human fetus.   Mielke G, Benda N. Circulation 2001; 103:1662-1668.

 To establish reference ranges for cardiac output and establish blood flow distribution in human fetuses, 222 normal fetuses underwent high-resolution echocardiograms.  Right cardiac output was 59% and left cardiac output was 41% of biventricular output.  Ductal blood flow was 46%, pulmonary flow 11%, and foramen ovale flow was 33% of biventricular output.

 ·                 Although cardiac output and distribution of blood flow have been well-studied in fetal animals, only limited data are available for human fetuses.  This excellent study clearly demonstrates right heart dominance in human fetuses.  Interestingly, the estimated ratio of pulmonary blood flow to cardiac output is higher than in fetal lamb studies.  This information will become particularly useful if fetal interventions are used in the future to improve the outcome for specific cardiac lesions.

 

 Delayed recognition of haemodynamically relevant congenital heart disease.  Pfammatter JP, Stocker FP. Eur J Pediatr 2001; 160:231-234. 

To evaluate the proportion of children with delayed diagnosis, this prospective study examined 323 consecutive pediatric patients requiring surgical or catheter interventional treatment for congenital heart disease.  32 (10%) had delayed diagnosis; the proportion of delayed diagnosis was similar in patients with cyanotic and acyanotic lesions.  7 of the 32 patients had complications due to delayed referral, but there was no mortality associated with late diagnosis.

 ·                 Although most children with congenital heart disease are diagnosed relatively promptly, this study shows a significant number of patients with significant heart defects had delayed diagnosis.  One interesting finding of this study was that all patients with late diagnosis had clinical cardiac findings other than systolic murmurs (increased precordial pulsation, fixed split S2, cyanosis, etc.) that should have alerted the physician to the possible presence of underlying heart disease.

 

Do patients over 40 years of age benefit from surgical closure of atrial septal defects?   Jemielity M, Dyszkiewicz W, Paluszkiewicz L, Perek B, Buczkowski P, Ponizynski A. Heart 2001; 85:300-303.

 76 patients, age 40-62 years of age underwent surgical closure of atrial septal defect (ASD), with one operative and one late death.  Pre-operatively, 47 (62%) were in NYHA functional classes III and IV; postoperatively, 61 (82%) were in classes I and II.  Echocardiography showed RV site decreased from 4.1 to 2.9 cm.

 ·                 Although some authors have found no differences in survival rates or symptoms in adults with ASD having surgery and those managed medically, in this relatively large group of patients, surgery was quite beneficial.  These patients with large left-to-right shunts, might also be expected to benefit from trans-catheter closure.  Although not emphasized by the authors, a key component of preoperative evaluation is measurement of pulmonary vascular resistance to rule out pulmonary vascular disease.  This study also highlights the need for improved early diagnosis (see previous review).

  

The Fontan procedure for tricuspid atresia: Early and late results of a 25-year experience with 216 patients.   Mair DD, Puga FJ, Danielson GK. J Am Coll Cardiol 2001; 37:933-939.

 216 patients with tricuspid atresia had nonfenestrated Fontan procedure over a 25 year period.  Overall survival was 79%; operative mortality declined and was 2% (1/58) in the most recent decade.  Age at operation had no effect on operative mortality, and late mortality was only increased in patients operated on at age 18 or older.  89% of surviving patients are in NYHA class I or II.  3 patients died of thromboembolic complications; one had a stroke.  Among the 167 surviving patients with follow-up, only 8 were receiving any form of anticoagulation therapy (warfarin, for mechanical mitral valve in 3 and for atrial arrhythmias in 5).  The risk of protein-losing enteropathy was 13.4% after 10 years.  The authors conclude that these results justify continued use of the nonfenestrated Fontan for children with tricuspid atresia.

 ·                 This large study, with relatively long follow-up, shows excellent results of the non-fenestrated Fontan in patients with tricuspid atresia.  Although several recent reports have advocated use of a fenestrated Fontan, there may still be a role for a non-fenestrated Fontan in tricuspid atresia.  It may never happen, but a large, randomized trial could answer many questions that remain for the Fontan:  1.) to stage, or not to stage; 2.) to fenestrate or not to fenestrate; and 3.) to anticoagulate, or not to anticoagulate.

  

Television watching, energy intake, and obesity in US children.  Crespo CJ, Smit E, Troiano RP, Bartlett SJ, Macera CA, Andersen RE. Arch Pediatr Adolesc Med 2001; 155:360-365.

 Using a nationally representative survey with an in-person interview and a medical examination, data were collected on 4069 US children, ages 8 to 16 years of age, between 1988 and 1999.  Obesity was lowest among children watching 0-1 hours of television per day, and highest among those watching 4 or more hours a day.  Girls engaged in less physical activity per day than boys.  The authors conclude that clinicians and public health interventionists should encourage active lifestyles in children.

 ·                 While hardly surprising, the results of this study (when considered along with other reports showing increasing inactivity, obesity, and type II diabetes among youth) are certainly alarming.  One would suspect that television viewing and inactivity among children, already at high levels in the years studied, may be even more common today.  We should all do our part to combat this growing epidemic (or perhaps encourage it to provide plenty of future patients for our adult cardiology colleagues).

 

 Long-term results of relief of subaortic stenosis in univentricular atrioventricular connection with discordant ventriculoarterial connections.

Jahangari M, Shinebourne EA, Ross DB, Anderson RH, Lincoln C.

Ann Thorac Surg 2001; 71:907-10.

 Between 1985 and 1998, 24 patients with univentricular atrioventricular connection to a dominant left ventricle and discordant ventriculoarterial connections underwent enlargement of ventricular septal defects for subaortic stenosis.  The median age at surgery was 3.2 years (range 3 weeks to 14 years). Median preoperative subaortic gradient was 46 mmHg. Operative mortality was 5/24 patients (21%). 10 year survival was 60%. Risk factors for mortality were age less than 1 year at operation, and the presence of obstruction in the aortic arch. Complete heart block occurred in 2 patients (8%).  Recurrent obstruction occurred in the first 2 patients of the series; subsequently patch enlargement of the rudimentary right ventricle was routinely added to the operation, with no further recurrences. At a median follow-up of 6.7 years (8 months to 13 years), 10 patients had undergone a Fontan operation, 5 a bidirectional Glenn shunt, and 2 cardiac transplantation.  

 ¨            Subaortic stenosis is a well-recognized complication in patients with univentricular atrioventricular connection to a dominant left ventricle and discordant ventriculoarterial connections. Subaortic stenosis can cause ventricular hypertrophy, which is a risk factor for a subsequent Fontan operation. One approach to this problem is surgical enlargement of the ventricular septal defect, which constitutes the subaortic outflow tract. This paper provides information on the long-term results of this approach, which are notable for good relief of obstruction, when combined with patch enlargement of the rudimentary right ventricle, and a low incidence of heart block. These results should be compared to those of the alternative Damus-Kaye-Stansel, or Norwood approach, particularly in patients under 1 year of age with aortic arch obstruction.

 

 Open commissurotomy for critical isolated aortic stenosis in neonates.

Alexiou C, Langley SM, Dalrymple-Hay MJR, Salmon AP, Keeton BR, Haw MP, Monro JL.

Ann Thorac Surg 2001; 71:489-93.

 25 consecutive neonates underwent open valvotomy for critical aortic stenosis between 1984 and 2000. The operative approach included cardiopulmonary bypass, cardioplegic myocardial arrest, and valvotomy under direct vision. 7 of the 25 patients (2 of whom died early) had hypoplastic left ventricles or associated cardiac defects, and were excluded from further analysis. Among the 18 remaining patients with isolated aortic stenosis, there was no operative mortality. At discharge, the mean aortic valve gradient was 37 mmHg; 6 patients had mild, and 2 moderate aortic insufficiency. At a mean follow-up of 8 years, 6 patients required reoperation, 3 of these a mechanical aortic valve replacement (at 9-11 years of age). 10 year freedom from aortic valve replacement was 79%, and from aortic reoperation or reintervention 55%. The mean valve gradient at last follow-up was 36 mmHg; 6 patients had mild, and 5 moderate aortic insufficiency.  

 ¨         This report serves as a reminder that open surgical valvotomy can give good results in neonates with isolated critical aortic stenosis. These results compare favorably with those of either percutaneous balloon valvotomy, or the Ross-Konno procedure. This approach, which includes circulatory support with cardiopulmonary bypass, may be particularly useful in the occasional patient who cannot be stabilized using prostaglandins and inotropes.

  

Survival after reconstructive surgery for hypoplastic left heart syndrome; a 15-year experience form a single institution.

Mahle WT, Spray TL, Wernovsky G, Gaynor JW, Clark BJ III.

Circulation 2000; 102:III-136-III-141.

 This paper reviews the long-term survival of patients undergoing reconstructive surgery for hypoplastic left heart syndrome at The Children’s Hospital of Philadelphia from 1984-1999. During this period, 840 patients underwent stage I (Norwood) surgery. Overall 10 and 15 year survival was 39%. Only 1 patient died beyond 5 years of age; only 5 patients underwent cardiac transplantation after initial surgical palliation. Later era of stage I surgery, age < 14 days and weight > 2.5 Kg at stage I were associated with significantly better survival.     

 ¨         Over the 15 year course of this review, the early- and intermediate-term survival for patients undergoing staged surgical palliation for hypoplastic left heart syndrome improved significantly. Among patients discharged to home after a Fontan procedure, subsequent death and cardiac transplantation were notably uncommon. This review provides an interesting look at a period of dramatic advances in the pre-, intra-, and postoperative management of patients with hypoplastic left heart syndrome. 

 

Ministernotomy versus full sternotomy in congenital heart defects; a prospective randomized study.

Luo W, Chang C, Chen S.

Ann Thorac Surg 2001; 71:473-5.

 100 patients undergoing repair of an atrial septal defect (34 patients) or ventricular septal defect (66 patients) were prospectively randomized to receive a lower ministernotomy, or a full sternotomy.  The ministernotomy approach included a 6-12 cm skin incision and division of the lower sternum. All operations were performed by a single surgeon. The mean patient age was 10 years. The ministernotomy group had significantly longer procedure times (from skin to skin), and shorter mean hospital stays (6.5 vs. 7.5 days, p = 0.02). There was no difference in myocardial ischemic time, cardiopulmonary bypass time, intubation time, ICU stay, or blood transfusions.  

 ¨         This study is notable for the facts that it was prospectively randomized, and that all the operations were by a single surgeon. It verifies that it is difficult to show any substantive difference between a ministernotomy and a full sternotomy approach in children undergoing congenital heart operations. While the ministernotomy group had shorter hospital stays, the difference was small, and hospital stay is quite variable from unit to unit. Nonetheless, as long as the ministernotomy approach provides equal safety and effectiveness, but preferable cosmesis, its appeal (particularly to patients and parents) is apparent.

 

 Developmental and neurologic effects of alpha-stat versus pH-stat strategies for deep hypothermic cardiopulmonary bypass in infants.

Bellinger DC, Wypij D, du Plessis AJ, Rappaport LA, Riviello J, Jonas RA, Newburger JW.

J Thorac Cardiovasc Surg 2001; 121:374-83.

 Patients undergoing reparative cardiac operations at less than 9 months of age using deep hypothermic cardiopulmonary bypass (with or without circulatory arrest) were enrolled in this single-center trial.  The patients were prospectively randomized to the use of alpha-stat versus pH-stat strategy for pH management during cardiopulmonary bypass. This report provides information on the developmental and neurologic outcomes at 1, and 2 to 4 years of age. Such information was available in 153 patients. The Psychomotor Development Index scores of the alpha-stat and pH-stat groups did not differ (P = 0.97). The Mental Development Index score of the pH-stat group was slightly higher for patients with transposition of the great arteries and tetralogy of Fallot, although the difference was not statistically significant. In contrast, the Mental Development Index score of the pH-stat group was significantly lower for patients with ventricular septal defect. There were no significant differences between the alpha-stat and pH-stat groups in abnormalities on neurologic or electroencephalographic examination at 1 year, or in parents’ rating of the children’s development or behavior at 2 to 4 years.

 ¨         During cardiopulmonary bypass, arterial pH and PCO2 may be managed by one of two strategies, alpha-stat (in which PCO2 is maintained at 40 mm Hg measured at 37oC and not corrected for the patient’s temperature), and pH-stat (in which PCO2 is adjusted to 40 mm Hg corrected to the patient’s temperature). In adults, neurologic outcomes appear to be better with the alpha-stat strategy.  In infants, several nonrandomized, retrospective reports suggest that neurologic outcomes may be better with the pH-stat strategy. The current study is the only randomized clinical trial of pH strategy in a pediatric population. In a previous report examining perioperative outcome in this cohort, the pH-stat strategy was associated with trends toward fewer deaths, fewer electroencephalographic seizures, shorter recovery time to first electroencephalographic activity, and (in patients with transposition) shorter duration of intubation and ICU stay (du Plessis et al. Perioperative effects of alpha-stat versus pH-stat strategies for deep hypothermic cardiopulmonary bypass in infants. J Thorac Cardiovasc Surg 1997; 114:991-1001). The current report examines neurodevelopmental outcome at 1 to 4 years in the same patient cohort. The use of alpha-stat versus pH-stat management was not consistently related to either improved or impaired neurodevelopmental outcomes. Given the large size, study design, and sophisticated neurodevelopmental follow-up, this study provides the most convincing answer to date on this controversy. 

 


 

From Other Journal / Pediatric Cardiology 22.5 (September/October 2001)

 

Prêtre R, Tamisier D, Bonhoeffer P, Maurlat P, Pouard, P, Sidi D, Vouhé P.  Results of the arterial switch operation in neonates with transposed great arteries.  Lancet 2001; 357:1826-1830.

 432 neonates underwent an arterial switch operation over a 13-year period.  The probability of survival at 10 years was 94%, and freedom from reoperation was 78% at 10 years.  26 patients died, 16 because of ischemia.  Risk factors for death were early experience, low weight, associated cardiac malformations such as right ventricular hypoplasia or aortic arch hypoplasia, and difficult coronary artery patterns.  Coronary artery pattern was less of a risk factor in recent years.  At most recent evaluation, 90% had normal lives without treatment, and 94% had normal function on echocardiogram.

 ·                 In this large series of unselected patients, excellent mid-term results are reported.  As the authors point out, coronary artery obstruction is the cause of most deaths and a substantial number of reoperations; attention should be focused on this area in these patients.  It appears likely that the long-term prognosis will be equally encouraging for patients undergoing arterial switch.

 

 Schmidt B, Davis P, Moddemann D, Ohlsson A, Roberts RS, Saigal S, Solimano A, Vincer M, Wright LL.  Long-term effects of indomethacin prophylaxis in extremely-low-birth-weight infants.  N Engl J Med 2001; 344:1966-1972.

 Soon after birth, 1202 infants with birth weights of 500 to 999 g were randomized to receive indomethacin or placebo once daily for 3 days.  Among infants receiving indomethacin, 47% died or survived with impairments, compared to 46% in those receiving placebo.  Patients receiving indomethacin had lower incidence of patent ductus arteriosus (24% vs 50% in placebo) and of severe periventricular and intraventricular hemorrhage (9% vs 13% in placebo).  The authors conclude that in extremely-low-birth-weight infants, prophylaxis with indomethacin reduces the incidence of patent ductus arteriosus and severe periventricular and intraventricular hemorrhage, though it does not improve the rate of survival without neurosensory impairment at 18 months.

 ·                 This large, multicenter trial clearly shows that prophylactic indomethacin reduces the incidence of patent ductus arteriosus and intracranial hemorrhage in extremely-low-birth-weight infants.  Unfortunately, this did not lead to better survival without neurologic damage, so that recommendations for using routine indomethacin prophylaxis do not appear to be unequivocal.

  

Mahle WT, Clancy RR, McGaurn SP, Goin JE, Clark BJ.  Impact of prenatal diagnosis on survival and early neurologic morbidity in neonates with the hypoplastic left heart syndrome.  Pediatrics 2001; 107:1277-1282.

 To determine if prenatal diagnosis reduces neurologic morbidity and operative mortality in patients who have palliative surgery for hypoplastic left heart syndrome (HLHS), data from 216 patients with HLHS were reviewed, including all patients with HLHS (but no lethal genetic anomaly) from a single institution over a five-year period.  37% had been diagnosed prenatally.  Overall hospital mortality was 26% and was similar in patients diagnosed prenatally and postnatally.  Using multivariate analysis, prenatal diagnosis of HLHS was associated with fewer adverse neurologic events than postnatal diagnosis (15% vs 26%).

 ·                 It is interesting that several studies, including this one, have failed to demonstrate a survival benefit for patients with HLHS diagnosed prenatally.  However, significantly improved neurologic outcome in prenatally diagnosed patients suggests that prenatal diagnosis of HLHS may be beneficial, likely by reducing the risk of preoperative hypoxia and ischemia.

 

 Simpson JM, Moore P, Teitel DF.  Cardiac catheterization of low birth weight infants.  Am J Cardiol 2001; 87:1372-1377.

 111 catheterizations were performed in 107 infants weighing less than 2.5 kg over 14 years at a tertiary-referral center.  31 procedures were interventional, including 16 with balloon atrial septostomy, 10 with collateral vessels in 3, all performed successfully.  One infant died while undergoing myocardial biopsy.  The reintervention rate for isolated pulmonary valve stenosis gradually increased to 71% (5 of 7) at one year.  Complications were more frequent in interventional (42%) than in diagnostic (16%) procedures.  The most common complications during interventions were arrhythmias (10%) and respiratory deterioration (10%).  The authors recommend that low birth weight infants should have elective intubation for interventional cardiac catheterization.

 ·                 In recent years, many centers have had increasing numbers of small patients requiring catheterization and intervention.  Despite this trend, limited data are available regarding the risks and complications in this group of patients.  This fine study provides useful information for anyone performing such studies.

 

 McElhinney DB, Clark BJ III, Weinberg PM, Kenton ML, McDonald-McGinn D, Driscoll DA, Zackai EH, Goldmuntz E.  Association of chromosome 22q11 deletion with isolated anomalies of aortic arch laterality and branching.  J Am Coll Cardiol 2001; 37:2114-2119.

 To determine the frequency of chromosome 22q11 deletions in patients with isolated anomalies of the aortic arch and its branches, 66 such patients were studied, including 22 with double aortic arch, 28 with right aortic arch and aberrant left subclavius artery; and others with various other isolated anomalies.  16 (24%) had 22q11 deletions, across the full spectrum of anomalies studied.

 ·                 As suggested by the authors, these findings should alert the clinician to consider deletion screening in patients with isolated anomalies of the aortic arch.

 
Dellgren G, Koirala B, Sakopoulus A, Botta A, Joseph J, Benson L, McCrindle B, Dipchand A, Cardella C, Lee K, West L, Poirier N, Van Arsdell GS, Williams WG, Coles JG.

Pediatric heart transplantation: improving results in high-risk patients.

J Thorac Cardiovasc Surg 2001; 121:782-91

 73 pediatric patients underwent heart transplantation between 1990 and 1999. An additional 22 of a total of 116 patients listed for transplant (19%) died on the waiting list. A cardioplegic solution containing blood and added insulin (vs. crystalloid-based cardioplegia) for the donor heart was introduced in 1997 and used in the 37 patients transplanted subsequently. 11 patients (10 of whom were  ≤1.2 years of age) underwent intentional transplantation with ABO-incompatible hearts, with 2 early and 1 late death. 13 patients required preoperative support with ECMO, with 3 early and 3 late deaths. Mean donor ischemic time was 255 minutes (range 51-610 minutes). Hospital mortality among the 73 patients transplanted was 14%. Survival at 5 years was 73%. Risk factors for death were ECMO (P = 0.05), and use of crystalloid donor cardioplegia (P = 0.08), but not ABO incompatibility or donor ischemic time.

 ¨         This study focuses on a number of unconventional strategies designed to increase the donor pool for pediatric heart transplantation. It demonstrates that ECMO can be used successfully as a bridge to transplant, although these patients remain at higher overall risk. Donor hearts with ischemic times up to 10 hours can also be successfully used. The interesting possibility of transplanting infants across ABO compatibility is documented.  

 

 Fraser CD, McKenzie ED, Cooley DA.

Tetralogy of Fallot: surgical management individualized to the patient.

Ann Thorac Surg 2001; 71:1556-63.

 In the management protocol followed in this report, patients requiring surgery at less than (roughly) 4 kg or 6 months of age underwent initial modified Blalock-Taussig shunt, followed by complete repair at 6-12 months of age. All other patients underwent complete repair after 6 months of age. From 1995 to 1999, 144 patients were operated for tetralogy of Fallot (129) or tetralogy of Fallot with atrioventricular septal defect (15). 94 patients had one stage complete repair, 39 had repair after initial shunt, and 10 await repair after shunt. The mean age at complete repair was 18 months. There were no operative, and 3 late deaths. There were no instances of surgical heart block. 4/133 patients (3%) have required reoperation after complete repair.

 ¨         This report serves as a reminder that a selective two stage approach to tetralogy of Fallot can give excellent results. The authors point out that by avoiding complete repair in small patients, this approach avoids the use of circulatory arrest, and minimizes the use of a ventriculotomy for VSD closure (transatrial, transpulmonary repair). Such a selective approach to complete repair of tetralogy may be preferred even in centers (such as this one) which are well-equipped to perform complete cardiac repairs in neonates.

 

 Bacha EA, Almodovar M, Wessel DL, Zurakowski D, Mayer JE Jr., Jonas RA, del Nido PJ.

Surgery for coarctation of the aorta in infants weighing less than 2 kg.

Ann Thorac Surg 2001; 71:1260-4.

 18 consecutive patients less than 2 kg underwent repair of aortic coarctation between 1990 and 1999. Median weight was 1330 gm (range 800 - 1950 gm). 15 were ductal-dependent, but none were operated emergently. All were repaired via left thoracotomy by resection and end-to-end anastomosis; 2 had additional reverse subclavian flap augmentation of the distal aortic arch. There were 1 hospital and 2 late deaths. 8 patients (44%) had residual or recurrent coarctation; 5 underwent balloon dilation and 3 reoperation. Risk factors for mortality were Shone’s syndrome or a hypoplastic aortic arch. The only risk factor for recoarctation was weight < 1.5 kg.   

 ¨         Aortic coarctation can be repaired in low-birth weight neonates, by standard techniques, with low risk. Recoarctation is common, but can also be managed at low risk. This report suggests that early repair will be preferable to delay in small neonates with coarctation. It also provides a good standard for comparison to the results of primary balloon dilation in such patients.

 


November/December 2001 issue [22.6]

Laudito A, Brook MM, Suleman S, Bleiweis MS, Thompson LD, Hanley FL, Reddy VM.

The Ross procedure in children and young adults: a word of caution.

J Thorac Cardiovasc Surg 2001; 122:147-53

 

72 patients underwent a Ross or Ross-Konno procedure between 1993 and 2000. Their median age was 9.1 years, with 81% being less than 15 years old. The indication for operation was aortic insufficiency (isolated or predominant) in 27 and aortic stenosis in 45. 12 patients had “autograft failure”, defined as either reoperation for severe autograft insufficiency (7 patients) or the development of at least moderate autograft insufficiency (5 patients). All 12 patients developed autograft failure more than one year postoperatively.  Among a variety of variables examined as predictors for autograft failure, only aortic insufficiency (isolated or predominant) as an indication for operation was a statistically significant risk factor.

 

¨         This study verifies an important incidence of failure after the Ross procedure, due to dilation of the autograft at the level of the annulus, the sinuses of Valsalva, and the sinotubular junction. It is also one of several which indicate that preoperative aortic insufficiency, and/or aortic annular dilation, is a risk factor for such autograft failure. It leaves open the question of whether technical modifications of the Ross procedure, such as external reinforcement of the annulus and sinotubular junction, can decrease, or avoid such failures.    


Huddleston CB, Balzer DT, Mendeloff EN.

Repair of anomalous left main coronary artery arising from the pulmonary artery in infants: long-term impact on the mitral valve.

Ann Thorac Surg 2001; 71:1985-9.

 

From 1980-2000, 16 patients less than 18 months of age underwent repair by reimplantation of the left coronary into the ascending aorta. 9 patients had moderate or severe mitral regurgitation preoperatively. Only one of these underwent concomitant mitral valve repair. There was one operative, and no late deaths at a mean follow-up of 6.9 years. 2 patients developed moderate or severe mitral regurgitation during follow-up. Both had initial improvement in regurgitation postoperatively, but then worsened over time. Both were found to have obstruction of the reimplanted left coronary, and were treated by mitral valve repair and left coronary revascularization 2 and 6 years after initial operation.   

 

¨         This series confirms the excellent results now achieved by direct reimplantation of the anomalous left coronary artery into the aorta. It also makes the interesting, and new observation that mitral insufficiency which worsens over follow-up suggests accompanying obstruction of the reimplanted left coronary.


Hutter PA, Thomeer BJM, Jansen P, Hitchcock JF, Faber JAJ, Meijboom EJ, Bennink GBWE.

Fate of the aortic root after arterial switch operation.

Eur J Cardio-thorac Surg 2001; 20:82-88

 

The diameter of the aortic root was followed by echocardiography in 144 patients who had undergone an arterial switch operation. 97 had transposition with an intact ventricular septum; 47 had an associated VSD.  21 underwent pulmonary artery banding prior to switch. Median follow-up was 8.6 years and ranged from 0.1-22 years. Following switch, the aorta at the level of the annulus had a mean Z-score of 1.5, which did not change significantly over time. The sinuses of Valsalva had a mean Z-score of 1.4, which also did not change significantly over time. The sinotubular junction (site of aortic anastomosis) had a mean Z-score which reached 0.8 at 4 months, and then showed little subsequent change. Patients with a VSD had an aortic annulus Z-score 0.75 larger than those without a VSD. Patients with preliminary pulmonary artery banding had similar aortic annulus and sinotubular junction sizes, but larger sinuses (by 2.8 Z-scores) than those without banding. No patient developed aortic stenosis. Only 5/144 (3.5%) had grade 2 or more aortic insufficiency.

 

¨         This report contains a great deal of detailed information on the size and function of the neo-aortic root after the arterial switch operation. Following arterial switch, the neo-aortic root at the level of the annulus, sinuses, and sinotubular junction is larger than normal. Over time, the aortic root increases in proportion to patient size, implying normal growth. Aortic root dilation in and of itself is rarely associated with significant aortic insufficiency.


Mahle WT, Gaynor JW, Spray TL.

Atrioventricular valve replacement in patients with a single ventricle.

Ann Thorac Surg 2001; 72:182-6.

 

From 1984-2000, 17 patients with single ventricles underwent atrioventricular valve replacement at the Children’s Hospital of Philadelphia. The median age at replacement was 3 years, with a range of 7 days - 17 years. Hospital mortality was 29%, with the last death occurring in 1993. The new onset of complete heart block was 44%. Age less than 2 years was a risk factor for operative mortality, and no patient less than 2 years old survived more than 6 months after operation. In late follow-up there were 4 deaths and 1 heart transplant. Among 7 late survivors, there were no reports of thromboembolism, bleeding, or valve re-replacement. 

 

¨         Atrioventricular valve replacement in patients with single ventricles is rare, as evidenced by the fact that the 17 patients in this report constitute only 1% of those undergoing single ventricle operations over the time of the study. This paper is the largest single review of this topic to date. As with most operations, results have improved over time. However, there remain significant risks of morbidity, and late mortality. Some risk may relate to the difficulties in accurately assessing ventricular function in the face of atrioventricular valve regurgitation. This paper also raises the possibility that patients under 2 years of age might be better served by heart transplantation.  


Alexiou C, McDonald A, Langley SM, Dalrymple-Hay MJR, Haw MP, Monro JL.

Aortic valve replacement in children: are mechanical prostheses a good option?

Eur J Cardio-thorac Surg 2000; 17:125-33

 

56 patients ranging in age from 1 to 16 years underwent aortic valve replacement with a mechanical prosthesis between 1972 and 1999.  Half of the patients underwent concomitant aortic root enlargement by division of the annulus into the anterior leaflet of the mitral valve (Nicks procedure). The mean size of the implanted valves was 22 mm (range 17 - 27). All patients were anticoagulated with coumadin, aiming for an INR of 2.5 - 3.0. Follow-up was for a mean of 7 years, a range of 0 - 26 years, and a total of 405 patient-years. Operative mortality was 3/56 (5%). There were 3 late deaths; actuarial survival at 20 years was 85%. Thromboembolism occurred at a rate of 0.3% / patient-year, with an actuarial freedom of 93% at 20 years. There was no incidence of bleeding requiring transfusion, nor any incidence of prosthetic valve endocarditis. Five patients require reoperation, none due to outgrowth of the valve. Actuarial freedom from reoperation at 20 years was 86%. 

 

¨         This report details the results of a long series of mechanical aortic valve replacements in children. The low rates of thromboembolism and bleeding are notable, although this data was retrospectively acquired. The liberal use of aortic root enlargement likely contributed to the low rate of reoperations. This series provides a good comparison to the results of homografts or autografts (Ross procedure) for aortic valve replacement in children.


Alexiou C, Galogavrou M, Chen Q, McDonald A, Salmon AP, Keeton BK, Haw MP, Monro JL.

Mitral valve replacement with mechanical prostheses in children: improved operative risk and survival.

Eur J Cardio-thorac Surg 2001; 20:125-113

 

44 patients ranging in age from 2 months to 16 years underwent mitral valve replacement with a mechanical prosthesis between 1981 and 2000.  23 patients were less than 5 years old, 9 were less than 1 year old. Indication for operation was mitral regurgitation in 36 and mitral stenosis in 8.  The mean size of the implanted valves was 24 mm (range 16 - 31). All patients were anticoagulated with coumadin, aiming for an INR of 3.0 - 3.5. Follow-up was for a mean of 6 years, a range of 0 - 18 years, and a total of 213 patient-years. Operative mortality was 6/44 (14%), but declined to 3.6% after 1990. There were 4 late deaths; actuarial survival at 10 years was 78%. Thromboembolism occurred at a rate of 0.9% / patient-year, with an actuarial freedom of 93% at 10 years. Bleeding occurred at a rate of 0.9% / patient-year, with an actuarial freedom of 98% at 10 years. Prosthetic valve endocarditis occurred at a rate of 0.9% / patient-year, with an actuarial freedom of 97% at 10 years. Eight patients required reoperation related to the mitral valve. Actuarial freedom from reoperation related to the mitral valve at 10 years was 75%. 

 

¨         This report details the results of a current series of mechanical mitral valve replacements in children. Mortality has declined in the last decade, and the rates of complications are quite low. This series provides an interesting comparison to the previously reviewed paper from the same group on mechanical aortic valve replacements, and that of Mahle et al on atrioventricular valve replacement in patients with single ventricles.

 

 

2002 Issues:


January/February 2002 issue [23.1]

Ringewald JM, Gidding SS, Crawford SE, Backer CL, Mavroudis C, Pahl E.  Nonadherence is associated with late rejection in pediatric heart transplant recipients.  J Pediatr 2001; 139:75-78.

 

To study the impact of nonadherence on late rejection after pediatric heart transplantation, the records of 50 patients surviving longer than 6 months were reviewed.  In 15 patients with 49 episodes of late rejection, 37 (76%) were associated with nonadherence.  7 of the 15 patients died, and 3 of 15 had coronary artery disease.  Risk factors for rejection were single parent home, non-white, older age, and higher cyclosporin A level variability (indicating nonadherence).  The authors conclude that late rejection after pediatric heart transplantation associated with nonadherence is common during adolescence, and is associated with poor outcome.

 

·                    Clearly, social issues are critical in patients being evaluated for and receiving cardiac transplantation.  This nice study emphasizes the importance of this, and provides useful information not only for transplant programs but also for pediatric cardiologists considering referral for transplantation.


Miller, MD, Porter CJ, Ackerman MJ.  Diagnostic accuracy of screening electrocardiograms in long QT syndrome I.  Pediatrics 2001; 108:8-12.

 

To evaluate the efficacy of the automated ECG as a screening tool for inherited long QT syndrome (LQTS), the authors used molecular testing of a proband and 22 family members to evaluate the KVLQTI mutation and symptomatic status.  13 were non-carriers, 5 were asymptomatic carriers, and 5 were symptomatic carriers.  All had standard ECGs.  Corrected QT interval (CQTI) was determined by computer and manually, and the accuracy of the computer ECG diagnostic interpretation was assessed.  Using a CQTI of   460 ms as a diagnostic cutoff, the positive and negative predictive values for identifying at-risk individuals was 100%.  However, 6 of 23 family members were erroneously classified by computer-derived ECG interpretation.  Further, half of the family members with a proven ion channel defect received a computer interpretation of "normal ECG."  The authors recommend that all first-degree relatives of a LQTS proband have a 12-lead ECG that is reviewed by a physician familiar with LQTS.

 

·                    As the authors emphasize, reliance on computer-generated ECG diagnostic interpretation alone will fail to identify many at-risk family members.  I always appreciate studies that suggest I will have future job security; however, at some point I suspect the computer programmers might succeed in improving automated computer interpretation of ECGs.  When that happens, the role of the pediatric cardiologist may become less important.  Until then, it appears we (pediatric cardiologists) are still needed for optimal ECG interpretation.


Amer-Wåhlin I, Hellsten C, Norén H, Hagberg H, Herbst A, Kjellmer I, Lilja H, Lindoff C, Månsson M, Mårtensson L, Olofsson P, Sundström AK, Marsál K.  Cardiotocography only versus cardiotocography plus ST analysis of fetal electrocardiogram for intrapartum fetal monitoring: a Swedish randomized controlled trial.  Lancet 2001; 358:534-538.

 

4966 women with term fetuses entered this randomized trial during labor, after a clinical decision was made to apply a fetal scalp electrode for internal cardiotocography.  They were randomly assigned monitoring with cardiotocography alone (CTG group) or cardiotocography plus ST analysis (CTG + ST group).  The CTG + ST group showed significantly lower rates of umbilical artery metabolic acidosis than the CTG group (0.7% vs. 2%), and of operative delivery for fetal distress (8% vs. 9%).  Differences were greater after exclusion of patients with malformations or inadequate recording.

 

·                    I found this large study very interesting and potentially beneficial for perinatal management.  I suspect that some of the neonatal ECGs I interpret show unusual ST-T segments because of the perinatal stress described in this paper.


Videlefsky N, Parks WJ, Oshinski J, Hopkins KL, Sullivan KM, Pettigrew RI, Fyfe D.  Magnetic resonance phase-shift velocity mapping in pediatric patients with pulmonary venous obstruction.  J Am Coll Cardiol 2001; 38:262-267.

 

33 patients (age 0.4 to 19.5 years) underwent magnetic resonance (MR) phase-shift velocity mapping of pulmonary venous (PV) pathways; results were compared with cardiac catheterization and Doppler echo data. MR imaging showed precise anatomical detail of the pulmonary veins in 7 patients with PV obstruction and 26 without obstruction.  Patients with obstruction had phase velocities of 100 to 250 cm/s, while controls had velocities of 20 to 71 cm/s; these results were similar to Doppler findings.  MR velocity mapping was 100% specific and 100% sensitive in detecting PV obstruction.  In the absence of left-to-right shunt lesions, PV velocities of 100 cm/s and greater indicated significant obstruction.

 

·                    In my opinion, one of the best uses for MRI is exploration of lesions that are sometimes difficult to evaluate by echocardiography, such as pulmonary venous malformations or obstruction.  This fine study shows the usefulness of this powerful modality in evaluating such patients.


Ahmad F, Kavey REW, Kveselis DA, Gaum WE, Smith FC.  Responses of non-obese white children to treadmill exercise.  J Pediatr 2001; 139:284-290.

 

A retrospective review of treadmill exercise studies on 347 white American children aged 5 to 18 years was performed with metabolic criteria to verify maximal exercise effort.  Exercise endurance time was lower in all age groups when compared with earlier published data.  The maximum systolic and diastolic BP increased with increasing age.  The authors conclude that lower exercise endurance times are seen despite physiologic evidence of maximal effort, and they suggest that cardiovascular conditioning may be reduced in contemporary American children.

 

·                    The gradual deconditioning of American youth is a trend I have noted with alarm over the past several years.  This study provides objective evidence of the poor level of fitness in a population of non-obese white children.  An important challenge is how best to respond to this important and emerging problem.

 

 

March/April 2002 issue [23.2]

Cao QL, Du ZD, Joseph A, Koenig P, Heitschmidt M, Rhodes J, Hijazi ZM.  Immediate and six-month results of the profile of the Amplatzer septal occluder as assessed by transesophageal echocardiography.  Am J Cardiol 2001; 88: 754-759.

 

The Amplatzer septal occluder (ASO) has shown promise in closing secundum atrial septal defects (ASDs), though there are concerns about the large profile of the device after closure.  To assess changes in profile of the device, the authors performed transesophageal echocardiography in 70 patients immediately after catheter closure of ASD by ASO, and at 6-month follow-up.  Median size of ASD was 14 mm (range 3 to 25); median size of device was 19 mm (range 8 to 34).  Complete closure was seen in 81% initially, and in 91% at 6-month follow-up.  Device thickness decreased by 42 to 48% over 6 months, from 12.2-12.5 mm to 6.3-6.5 mm.

 

·                    Although the ASO appears to be quite effective in ASD closure in the short-term, long-term results are not yet available.  This excellent study provides valuable information, showing that one concern in use of this device, its high profile, appears to improve after initial deployment.


Channick RN, Simmoneau G, Sitbon O, Robbins IM, Frost A, Tapson VF, Badesch DB, Roux S, Rainsio M, Bodin F, Rubin LJ.  Effects of the dual endothelin-receptor antagonist bosentan in patients with pulmonary hypertension: A randomised placebo-controlled study.

 

Endothelin I, an endogenous vasoconstrictor and mitogen, appears to play an important role in pulmonary hypertension (PHT).  Patients with severe PHT have elevated levels of endothelin.  This study was undertaken in order to evaluate the efficacy and safety of bosentan, a dual endothelin-receptor antagonist that can be taken orally, in patients with severe PHT.  32 patients with PHT (primary or associated with scleroderma) were randomly assigned to bosentan or placebo for at least 12 weeks.  Patients receiving bosentan had significantly improved exercise capacity (6 minute walk distance increased by 70 meters vs. decreasing by 6 meters in controls), higher cardiac index (1.0 l/min/m2 greater than controls), and decreased pulmonary vascular resistance (PVR decreased by 223 dyn s cm–5 vs. increasing by 191 dyn s cm-5 in controls).

 

·                    Bosentan, an antagonist of both endothelin subtypes (ETA and ETB) has been studied in rats with chronic pulmonary hypertension, and was found to reduce pulmonary arterial pressure, pulmonary vascular hypertrophy, and right ventricular hypertrophy, without inducing systemic vasodilation.  This intriguing, randomized, placebo-controlled trial suggests that bosentan may also prove useful for short- and long-term treatment of humans with PHT.  Treatment of patients with PHT is often challenging, and while primary PHT in children is quite rare, secondary PHT (e.g., from congenital heart disease or from cardiomyopathy), which was not addressed in this study, is more common.  Until now, treatment modalities have been limited and either invasive or not very effective (heart-lung transplant, intravenous continuous prostacyclin, or traditional medical support).  I look forward to further studies to clarify the role of this apparently powerful substance for treatment of PHT.

 


Jenkins PC, Flanagan MF, Sargent JD, Canter CE, Chinnock RE, Jenkins KJ, Vincent RN, O'Connor GT, Tosteson ANA.  A comparison of treatment strategies for hypoplastic left heart syndrome using decision analysis.  J Am Coll Cardiol 2001; 38:1181-1187.

 

Decision analysis is a modeling technique that structures a problem into choices, chance events, and outcome measures.  It is used to provide a framework for quantitatively identifying the treatment strategy that, on average, has the highest chance of success.  This technique was used to compare six strategies used to treat hypoplastic left heart syndrome (HLHS): staged surgery, transplant (Tx), stage 1 surgery as an interim to Tx, and listing for transplant for 1, 2, or 3 months before performing staged surgery if a donor is unavailable.  Probabilities were derived from the literature and a dataset of 231 patients with HLHS born between 1989 and 1994.  Using this technique, the authors found that if a donor is available within one month, Tx is the optimal choice; if no donor is found by that time, stage 1 surgery should be performed.  Centers with organ donation rates less than 10% in 3 months and with stage 1 mortality less than 20% should have staged surgery.  If the 3-month organ donation rate is greater than 30%, waiting one month on the transplant list would optimize survival.

 

·                    As the treatment for HLHS has evolved in recent years, various strategies have been proposed to improve treatment of this challenging group of patients.  The novel technique of decision analysis offers an interesting perspective which may help pediatric cardiologists make the best treatment decisions for patients with HLHS.


Häusler M, Hübner D, Delhaas T, Mühler EG.  Long term complications of vena cava thrombosis.  Arch Dis Child 2001; 85: 228-233.

 

A combined retrospective and prospective study on infants and children with inferior vena cava (IVC) thrombosis was performed, to evaluate outcomes in such patients.  40 patients were included, including 4 who had cardiac catheterization, 18 with central venous saphenous lines, and 8 with umbilical venous catheters.  6 died within 3 months of diagnosis, and one was lost to follow-up.  Among the 33 surviving patients, 12 had limited IVC thrombosis, none of whom showed persisting caval obstruction.  Among the 21 with extensive IVC thrombosis, caval flow was only established in 4 (one thrombolysis, 2 surgery, one spontaneous revascularization).  In the 17 patients with persisting obstruction, 12 had varicose veins, and 7 of these had post-thrombotic syndrome.

 

·                    Previous, smaller studies have identified IVC thrombosis as a complication with significant morbidity.  This excellent study provides specific information describing the outlook for patients with IVC thrombosis.  As the authors suggest, central venous catheters, a probable contributing factor in a majority of cases here, should be used only if essential.


Ekman Joelsson BM, Sunnegårdh J, Hanseus K, Berggren H, Jonzon A, Jögi P, Lundell B.  The outcome of children born with pulmonary atresia and intact ventricular septum in Sweden from 1980 to 1999.  Scand Cardiovasc J 2001; 35: 192-198.

 

The records of all children born in Sweden with pulmonary atresia and intact ventricular septum (PA-IVS) over a 20-year period were reviewed.  A total of 84 children were born with this diagnosis.  7 died prior to surgery; 77 had operations, with a one-year survival rate of 75%.  36 children had ventriculocoronary communications, with a one-year survival rate of 50%.  At the end of the study period, 52 children (62%) were alive, 32 with biventricular repair and 1 with univentricular repair.

 

·                    This large study nicely shows the clinical course of patients with PA-IVS, and points out possible areas of improvement in such patients.  Clearly, early diagnosis with appropriate treatment is important in this lesion.  One area of particular concern is patients with ventriculocoronary communications, and I agree with the authors' recommendations that the right ventricle should be decompressed in all children except for those with a diminutive RV, muscular pulmonary atresia, and RV-dependent coronary circulation.  As they also point out, angiocardiographic evaluation of the coronary arteries is essential for determining the coronary circulation.


Mokdad AH, Bowman BA, Ford ES, Vinicor F, Marks JS, Koplan JP.  The continuing epidemics of obesity and diabetes in the United States .  JAMA 2001; 286: 1195-1200.

 

To estimate the prevalence of obesity, diabetes, and use of weight control strategies among US adults, a random-digit telephone survey was conducted in all states, with 184,450 adults responding in the year 2000.  Using self-reported heights, weights, and presence of diabetes, the prevalence of obesity was 19.8%, prevalence of diabetes was 7.3%, and both combined was 2.9%.  27% did not engage in any physical activity, and another 28% were not regularly active.  76% consumed less than the recommended 5 or more servings of fruits and vegetables per day.  Compared to a similar 1991 survey of 47 states, obesity had increased significantly; in 1991, 4/47 had obesity rates of 15% or greater; in 2000, 49/50 had rates of 15% or greater.  In 1991, none of the participating states had obesity rates of 20% or greater; in 2000, 22/50 had this rate.  The prevalence of diabetes also increased over this period, from 4.9% in 1991 to 7.3% in 2000.

 

·                    Although this is a study of US adults, I included it in the journal review because the risk factors described (overweight, diet, activity) all involve behaviors that start in childhood.  Since people are creatures of habit, it is important that good habits are established as early as possible, if cardiovascular disease of adulthood (myocardial infarction, stroke) is to be avoided.  I have observed with alarm these same trends in my pediatric cardiology clinic, and I fear that if current trends are not reversed, these lifestyle choices will claim far more lives than terrorism or biological weapons.


Duncan BW, Bohn DJ, Atz AM, French JW, Laussen PC, Wessel DL.

Mechanical circulatory support for the treatment of children with acute fulminant myocarditis.

J Thorac Cardiovasc Surg 2001; 122:440-8

 

This report summarizes the courses of 15 children with acute myocarditis, who were supported with either extracorporeal membrane oxygenation (12 patients), or ventricular assist devices (3 patients). The patients constitute a consecutive series over the years 1990-97 from 3 institutions, Boston Children’s Hospital, Toronto Hospital for Sick Children, and Seattle Children’s Hospital. The 15 patients represent 14% of 102 patients admitted to the ICU for acute myocarditis. Their median age was 4.6 years, and ranged from 1 day to 13 years. Myocardial biopsy in 12 of the patients demonstrated inflammatory infiltrates or necrosis in 8 cases. Nine of the 15 patients were successfully weaned from support, with 7 survivors. The length of support in those successfully weaned ranged from 5-16 days. The remaining 6 patients underwent heart transplantation, with 5 survivors. Thus overall survival was 12/15 patients (80%). Despite marked ventricular dysfunction at presentation, the 7 survivors who were not transplanted had normal ventricular function at a median follow-up of 1.1 years.   

 

¨         This study documents good results of mechanical circulatory support in a small group of patients with acute fulminant myocarditis. Due to the bleeding and infectious complications of transthoracic cannulation, the authors conclude the preferred approach is ECMO via peripheral cannulation. If required, additional decompression of the left side of the heart can be achieved by balloon atrial septostomy. Patients with histologic evidence of acute myocarditis can be managed with the expectation of return of native ventricular function in most cases.   


Ohye RG, Gomez CA, Ohye BJ, Goldberg CS, Bove EL.

The Ross/Konno procedure in neonates and infants: intermediate-term survival and autograft function.

Ann Thorac Surg 2001; 72:823-30.

 

From 1993 to 2000, 10 patients under 1 year of age underwent a Ross/Konno procedure (pulmonary autograft aortic valve replacement with aortic annulus enlargement). Their median age was 16 days; 6 were neonates. All had critical or severe aortic stenosis; 3 had previous balloon valvotomy. There were no deaths, operative or late. At a median follow-up of 4 years, no patient had more than mild aortic stenosis, while 2 had 2-3+ aortic insufficiency. Over time, aortic annulus Z values were relatively unchanged. Sinotubular junction Z values increased by +2 at 1 year, then tended to remain stable. The 2 patients with significant aortic insufficiency also had the largest increases in sinotubular junction Z value over time. 2 patients required pulmonary allograft reoperation; none underwent reoperation on the left ventricular outflow tract.

 

¨         While the Ross procedure has become increasingly popular in children and young adults, there is relatively little information available on its use in infants and neonates. This series demonstrates excellent short and mid-term results in a small number of infants, including 6 neonates. Postoperatively, the aortic annulus tended to increase in size in proportion to somatic growth. This finding suggests autograft growth, clearly an important issue in such young patients. As in several other Ross series in older patients, sinotubular junction dilation associated with aortic insufficiency was observed in some patients during follow-up. 


Isomatsu Y, Imai Y, Shin’oka T, Aoki M, Sato K.

Coarctation of the aorta and ventricular septal defect: should we perform a single-stage repair?

J Thorac Cardiovasc Surg 2001; 122:524-8

 

79 patients younger than 3 months of age underwent 2-stage repair of coarctation and VSD between 1984 and 1998. VSD location was perimembranous in 59%, subpulmonary in 35%, and muscular in 5%. Aortic arch hypoplasia (defined as narrowest arch diameter <4mm) was present in 27 (34%) patients. The first stage operation consisted of subclavian flap angioplasty and pulmonary banding; the second stage of pulmonary debanding and VSD closure. The mean interval between stages was 10 months. There were 2 operative deaths at first stage, 2 at second stage, and 2 late after second stage. Actuarial survival at 10 years was 92%. Freedom from recoarctation at 10 years was 90%. The 7 patients with recoarctation were all successfully treated by balloon dilation. Neither age nor aortic arch hypoplasia was a predictor of recoarctation.

 

¨         Optimal management of the infant with aortic coarctation and VSD remains controversial. This series demonstrates the excellent results that can be achieved with a 2-stage approach. It is of interest that arch hypoplasia, which can be quite marked in patients with coarctation and associated VSD, was not addressed in the coarctation repairs, which consisted of subclavian flaps in all patients. Despite this, recoarctation was infrequent, was not associated with arch hypoplasia, and was well dealt with by balloon dilation. This implies the recoarctations were at the coarctation repair site, rather than in the arch, and that the hypoplastic arches exhibited “catch-up” growth following coarctation repair. This report provides a good comparison for several recent series of single-stage complete repair of coarctation and VSD.


Lofland GK.

The enhancement of hemodynamic performance in Fontan circulation using pain free spontaneous ventilation

Eur J Cardio-thorac Surg 2001; 20:114-19

 

50 consecutive patients undergoing either a bidirectional Glenn shunt (23 patients) or a Fontan procedure (27 patients) had pulmonary artery pressures monitored in the early postoperative period. 12 of the patients also had continuous monitoring of cardiac output, using an extravascular Doppler probe placed on the ascending aorta. Anesthetic management was aimed at early extubation and included continuous narcotics, along with caudal, epidural or spinal blocks. All patients were extubated in the operating room or within 2 hours of arrival in the ICU. Mean pulmonary artery pressure fell from 19 mmHg pre-extubation to 14 mmHg immediately following extubation. Cardiac index (in 12 patients) rose from 3.2 pre-extubation to 5.0 immediately following extubation.

 

¨         This paper nicely demonstrates the hemodynamic advantages of spontaneous ventilation compared to mechanical ventilation patients with a venous source of pulmonary blood flow. It adds to the information supporting early extubation as a management objective in patients undergoing a superior cavopulmonary connection or Fontan procedure.


Danton MHD, Barron DJ, Stumper O, Wright JG, DeGiovannni J, Silove ED, Brawn WJ.

Repair of truncus arteriosus: a considered approach to right ventricular outflow tract reconstruction.

Eur J Cardio-thorac Surg 2001; 20:95-104

 

61 infants undergoing repair of truncus arteriosus between 1988 and 2000 were retrospectively reviewed. RV to PA continuity was by a valved conduit in 38 (homograft in 28, xenograft in 10), or a direct anastomosis between the pulmonary arteries and the right ventricle in 23. Operative mortality was 8% in the conduit group and 22% in the direct anastomosis group (P = 0.23). Survival beyond 2 years was 77% in the conduit group and 67% in the direct anastomosis group (P = 0.25). Freedom from reoperation on the right ventricular outflow tract beyond 4 years was 58% in the conduit group and 89% in the direct anastomosis group (P = 0.03). Freedom from all reintervention (either reoperation or balloon dilation) was 50% in the conduit group and 68% in the direct anastomosis group. (P = 0.12).      

 

¨         This report focuses on the results of two general approaches to right ventricular outflow tract reconstruction in primary repair of truncus arteriosus. While not randomized, it does include a reasonable number of patients in the two groups, operated at a single institution. Compared to a valved conduit, direct anastomosis offered a significantly lower reoperation rate at 4 years, but carried a similar rate of all reinterventions, and tended to have a higher operative mortality. This information supplements that in several recent series of truncus arteriosus repair which report low (5%) operative mortality rates in neonates, exclusively utilizing a valved conduit for right ventricular outflow tract reconstruction.

 

 

May/June 2002 issue [23.3]

Jaeggi ET, Hamilton RM, Silverman ED, Zamora SA, Hornberger LK.  Outcome of children with fetal, neonatal, or childhood diagnosis of isolated congenital atrioventricular block: A single institution's experience of 30 years.  J Am Coll Cardiol 2002; 39:130-137.

 

In order to identify predictors of mortality and the requirement for pacemakers, the authors reviewed the records of all cases with isolated congenital third-degree atrioventricular block (CAVB) over 34 years.  Of 102 cases identified, 29 were diagnosed in utero (F), 33 as neonates (N), and 40 as children (C) at 5.7 4.8 years of age.  Anti-Ro and/or anti-La were found in 95% of F, 90% of N, and 5% of C mothers.  Patients with CAVB having F, N, and C diagnosis had respective mortalities of 43%, 6%, and 0% in the first two decades of life.  Increased mortality risk was associated with F diagnosis (13/15 deaths), fetal hydrops (6/6), endocardial fibroelastosis (5/5 cases), and delivery at 32 weeks (4/6 cases).  At 20 years of age only 11% of N and 12% of C patients were not paced.

 

·                    Because cases of isolated congenital atrioventricular block are rare, there are few large studies of such patients.  This large, retrospective study demonstrates high fetal and neonatal mortality in patients with CAVB and shows that most patients with this diagnosis undergo pacemaker placement by adulthood.  This high-risk group of patients requires intensive management, and this excellent study helps our understanding of this rare disorder.


Tutar HE, Atalay S, Türkay S, Imamoglu A.  QRS axis in isolated perimembranous ventricular septal defect and influences of morphological factors on QRS axis.  J Electrocardiol 2001; 34:197-203.

 

The authors retrospectively analyzed the electocardiograms of 59 children with an isolated ventricular septal defect.  20% had left axis deviation, which was more common with than without ventricular septal aneurysm (40% vs. 8%).  Mild right ventricular hypertrophy was also more common in patients with ventricular septal aneurysm.

 

·                    I was previously unaware of any ECG changes associated with septal aneurysm and VSDs.  A useful paper for anyone interested in the ECG findings in patients with an isolated ventricular septal defect.


Vizza CD, Sciomer S, Morelli S, Lavalle C, Di Marzio P, Padovani D, Badagliacca R, Vestri AR, Naeije R, Fedele F.  Long term treatment of pulmonary arterial hypertension with beraprost, an oral prostacyclin analogue.  Heart 2001; 86:661-665.

 

To evaluate the effects of one year's treatment with berapost, 13 patients with severe pulmonary hypertension were studied.  After one month of treatment, NYHA class decreased from 3.4 to 2.9, the six-minute walking distance increased from 213 to 276 meters and systolic pulmonary artery pressure decreased from 93 to 85.  One patient died after 40 days (from right heart failure) and another was lost to follow-up.  The remaining 11 had improved functional class and exercise capacity, as well as decreased systolic pulmonary artery pressure for the remaining 11 months of the study, with minor side effects.

 

·                    Although therapeutic options for patients with severe pulmonary hypertension have been limited, with significant morbidity and mortality, there now seems to be some reason for optimism regarding future therapy for such patients.  Continuous prostacyclin, given by intravenous infusion, has become an established treatment option, and several studies, including this one, have demonstrated efficacy of other agents.  Besides beraprost and other oral prostacyclin analogues, other agents showing promise include inhaled and subcutaneous prostacyclin, endothelin antagonists (bosentan), and phosphodiesterase inhibitors (suldenafil).  This nice study showed improvement in exercise capability and pulmonary artery pressures in patients with severe pulmonary hypertension who received beraprost for one year.  I look forward to future, longer studies using this and other agents.


Wu MH, Wang JK, Lin JL, Lai LP, Lue HC, Hsieh FJ.  Cardiac rhythm disturbances in patients with left atrial isomerism.  PACE 2001; 24:1631-1638.

 

In order to study sinus node and AV conduction tissue function in patients with left atrial isomerism, 22 such patients were identified and followed for 2-276 months (mean 90).  Associated anomalies included interruption of the inferior vena cava (82%), common atrium (41%), AV canal (64%), double outlet right ventricle (36%), and pulmonary stenosis (68%).  16 had palliative interventions.  During follow-up, 64% developed bradyarrhythmia (at median 78 months), including junctional rhythm in 11, sinus bradycardia in 8 (5 also had junctional rhythm) and AV block in 2.  None of the bradyarrhythmias was directly related to surgery.  The probability of being free from bradyarrhythmias was 80% at 2 years and 46% at 6 years.  Of the 6 patients who had a Fontan-type operation, 3 developed post-operative junctional ectopic tachycardia.

 

·                    Because the sinus node is a right atrial structure, patients with left atrial isomerism (who have no morphologic right atrium) often have disturbances of atrial rhythm.  I find atrial isomerism is a fascinating subject, but because cases are rare, and cases historically were often lethal, specific and meaningful clinical information in the past has been difficult to find.  As the treatment of complex cardiac lesions has improved, and such patients have a better prognosis, clinical details (such as the rhythm disturbances outlined in this study) take on increased significance.  This report provides a nice addition in clinical information for a rare but complex group of patients.


Duke C, Sharland GK, Jones AMR, Simpson JM.  Echocardiographic features and outcome of truncus arteriosus diagnosed during fetal life.  Am J Cardiol 2001; 88:1379-1384.

 

This study's goal was to analyze, retrospectively, the echocardiographic features and outcome of fetuses with truncus arteriosus.  At presentation, truncus was firmly diagnosed in 16 and was a differential diagnosis in 12.  14 of 16 (87%) of the firm diagnoses were correct, and there were 17 confirmed cases of truncus.  Pregnancy was terminated in 4, with 13 live births.  One was not actively treated, 4 died preoperatively, and 8 (61%) had surgery.  30-day surgical mortality was 2 of 8 (25%), there was one late death after cardiac catheterization, and overall survival on an intention-to-treat basis was 5 of 12 (42%).  5 of 6 patients with elevated truncal Doppler velocity in utero had post-natal truncal valve stenosis.  Two fetuses with stenotic valves had sudden death prior to surgery.  The authors recommend counseling parents of fetuses with truncus that this lesion carries a relatively high mortality.

 

·                    Although the outcome for children with truncus arteriosus has improved, no previous studies have followed the natural history of this condition following fetal diagnosis.  By including all cases of fetal truncus, and following them, the authors demonstrated that accurate prenatal diagnosis of this complex lesion is possible.  Unfortunately, the study also appears to indicate that significant mortality is still be a hallmark of this lesion.


Milanesi O, Stellin G, Colan SD, Facchin P, Crepaz R, Biffanti R, Zacchello F.  Systolic and diastolic performance late after the Fontan procedure for a single ventricle and comparison of those undergoing operation at < 12 months of age and at > 12 months of age.  Am J Cardiol 2002; 89:276-280.

 

To see if surgical history can influence properties of a functional single left ventricle after Fontan operation, the authors performed echoes on 21 patients who were > 12 months of age at the time of surgery (group A) and 10 patients who were < 12 months at the time of surgery (group B).  Group A had persistently elevated left ventricular mass index, while group B had normal left ventricular mass.  Both groups had increased late diastolic filling, which was unrelated to length of follow-up.

 

·                    As the authors note, these data suggest that patients with a single left ventricle who undergo an unloading procedure have normalization of left ventricular mass, although a diastolic filling pattern of increased compliance persists, regardless of the age at operation.  A useful report for all who are involved in deciding the optimal timing of the Fontan operation for patients with a single ventricle type of physiology.

 


Mavroudis C, Backer CL, Deal BJ, Johnsrude C, Strasburger J. Total cavopulmonary conversion and maze procedure for patients with failure of the Fontan operation. J Thorac Cardiovasc Surg 2001;122:863-71.

 

Between 1994 and 2001, 40 patients underwent Fontan conversion and arrhythmia surgery. 31 of the 40 patients had previous atriopulmonary Fontan procedures. The mean age at Fontan conversion was 18 years. Arrhythmia surgery evolved from cryoablation of the isthmus between the coronary sinus and inferior vena cava (10 patients), to a modified right atrial maze in patients with atrial reentry tachycardia (16 patients), and a combined right and left atrial maze (maze-Cox III operation) in patients with atrial fibrillation (14 patients).  38 of the 40 patients had concomitant placement of a permanent pacemaker (atrial in 33 and dual-chamber in 5). There was no operative mortality. Three patients required heart transplantation from 8 days to 33 months postoperatively. Mean follow-up was 30 months. Among the patients undergoing a modified right atrial maze, none had recurrence of supraventricular tachycardia. Among those undergoing a maze-Cox III operation, 29% had perioperative supraventricular tachycardia, but none had tachycardia in follow-up.

 

¨         Since its introduction in the mid-1990s, Fontan conversion has resulted in significant hemodynamic improvement in patients with failing Fontan operations. Unfortunately, isolated Fontan conversion has provided inconsistent control of atrial arrhythmias, despite the fact that it may include removal of a portion of the atrium and elimination of high pressure within the atrium. The Chicago Memorial group has pioneered the concept of adding antiarrhythmia surgery to Fontan conversion. Their approach includes both the placement of specific intra-atrial lesions, and the placement of a permanent transmural pacemaking lead for antitachycardia and bradycardia pacing therapies. This report documents their evolution to a standardized right atrial approach for atrial reentry tachycardia, and a combined right and left atrial approach (maze-Cox III operation) for atrial fibrillation. At a mean follow-up of 2.5 years, there has been excellent control of atrial arrhythmias, which is a clear improvement over Fontan conversion alone. It will be of interest to see the longer-term outcomes in these patients.


Tabbutt S, Ramamoorthy C, Montenegro LM, Durning SM, Kurth CD, Steven JM, Godinez RI, Spray TL, Wernovsky G, Nicolson SC.  Impact of inspired gas mixtures on preoperative infants with hypoplastic left heart syndrome during controlled ventilation.  Circulation 2001; 104(suppl I):I-159-I-164.

 

This study evaluates the effects of inspired nitrogen (hypoxia), and carbon dioxide (hypercarbia) in preoperative neonates with hypoplastic left heart syndrome. Ten neonates were prospectively studied while anesthetized, paralyzed and mechanically ventilated. Nitrogen (to produce an FiO2 = 17%) and carbon dioxide (2.7%) were administered to each patient in a random order. Mixed venous oxygen saturation was measured via a line in the superior vena cava. Arteriovenous oxygen saturation difference was used as a measure of systemic oxygen delivery. Inspired nitrogen decreased both systemic and mixed venous oxygen saturation by 5%, but did not alter arteriovenous oxygen saturation difference. Inspired carbon dioxide decreased systemic oxygen saturation by 2%, but  increased mixed venous oxygen saturation by 6%, so that arteriovenous oxygen saturation difference decreased by 8%.

 

¨         Preoperative management of neonates with hypoplastic left heart syndrome frequently includes interventions aimed at decreasing the ratio of pulmonary to systemic blood flow (Qp:Qs), and increasing systemic oxygen delivery. These interventions can include the use of inspired nitrogen to produce hypoxia, or inspired carbon dioxide to produce hypercarbia. This is the first report to study these interventions in preoperative neonates. The study is well designed, with prospective, randomized crossover use of the two interventions, and control of many patient and management variables. While inspired nitrogen (hypoxia) did decrease systemic oxygen saturation, and probably Qp:Qs, it did not increase systemic oxygen delivery. In contrast, inspired carbon dioxide (hypercarbia) did increase systemic oxygen delivery.


Fedderly RT, Whitstone BN, Frisbee SJ, Tweddell JS, Litwin SB. Factors related to pleural effusions after Fontan procedure in the era of fenestration. Circulation 2001; 104(suppl I):I-148-I-151.

 

From February 1991 to April 2000, 98 patients underwent a fenestrated Fontan procedure at Children’s Hospital of Wisconsin . A variety of patient-related variables were retrospectively analyzed for their effect on the duration of pleural effusions after operation. The mean duration of effusions was 14 days; 32% of patients drained effusions for longer than 2 weeks. The mean length of hospital stay was 18 days. The 2 factors, which were statistically significantly related to longer duration of effusions and length of stay, were age less than 4 years, and performance of the operation during the winter respiratory viral season (November – March).

 

¨         This study makes the interesting observation that performance of a fenestrated Fontan procedure during the winter respiratory viral season in Wisconsin was associated with prolonged pleural effusions and longer hospital stays. The authors point out that limiting Fontan operations during the winter, and/or routine preoperative screening for viral infections may be indicated. It will be interesting to see whether this observation applies in other regions.


Losay J, Touchot A, Serraf A, Litvinova A, Lambert V, Piot JD, Lacour-Gayet F, Capderou A, Planche C. late outcome after arterial switch operation for transposition of the great arteries. Circulation 2001; 104(suppl I):I-121-I-126.

 

Twelve hundred patients underwent an arterial switch operation for transposition of the great arteries between 1982 and 1999. The 1095 survivors have been prospectively followed. Median follow-up was 4.9 years (range 0.5-17 years). There were 32 late deaths, at a median of 2.7 months, and all within the first 5 years. Survival rate (including operative mortality) was 88% at 10 and 15 years. Freedom from reoperation was 82% at 10 and 15 years. The hazard function for reoperation declined early, but then slowly increased after 3 years. The most common cause of reoperation was pulmonary stenosis, which occurred up to 9 years after arterial switch. Reoperations for aortic insufficiency and coronary obstruction were rare (13 and 6 patients respectively), but occurred throughout the follow-up period. Incidence of grade II aortic insufficiency was 5% at 5 years and 9% at 15 years. Normal left ventricular function was present in 96% and sinus rhythm in 98%. 278 patients had coronary angiography; 8% had coronary lesions. 

 

¨         This study provides extensive follow-up information out to 17 years in a large number of patients who have undergone the arterial switch operation. Late mortality was rare and not seen after 5 years. Reoperations occurred in 10% of patients and were observed throughout the follow-up period. Aortic insufficiency had a low prevalence, but an incidence which continued to increase with length of follow-up. Coronary stenosis was also rare, but observed both early and late. As found in other series, good left ventricular function and sinus rhythm were seen in almost all patients. Continued surveillance for pulmonary stenosis, aortic insufficiency and coronary stenosis remains appropriate late after the arterial switch operation.

 

July/August 2002 issue [23.4]

Jacobs ML, Pourmoghadam KK, Geary EM, Reyes AT, Madan N, McGrath LB, Moore JW. Fontan’s operation: Is aspirin enough? Is coumadin too much? Ann Thorac Surg 2002;73:64-8.

 

Between 1996 and 2000, 72 patients underwent Fontan procedures. Management details included (1) avoidance of caval cannulation and central venous lines (2) inotropic support for 48-72 hours postoperatively to maintain cardiac output (3) avoidance of blind pulmonary artery stumps, and (4) administration of aspirin (81 mg per day) beginning on postoperative day 1. All patients had undergone previous superior cavopulmonary connections. The Fontan procedure was an intra-atrial lateral tunnel (with 3 separate 2.5mm fenestrations) in 65 patients, and an extracardiac conduit in 7 patients. Thromboembolic monitoring included postoperative transesophageal echocardiography,  transthoracic echocardiography during follow-up, and cardiac catheterization 1 year after operation (in 54/72 patients). There were no operative or late deaths. During a mean follow-up of 40 months, there were no documented thromboembolic events, and no aspirin-related complications.

 

¨         There are many potential causes of thromboembolism after Fontan’s operation. Appropriate anticoagulation is debated and varies among institutions. This report demonstrates that, when combined with the management details described, aspirin alone provides effective anticoagulation, and routine use of more aggressive anticoagulation (coumadin) does not seem warranted. While some of the specific management details may not be necessary, the excellent results of this approach are compelling.  Whether these recommendations apply to patients at potentially higher thromboembolic risk (older patients, marginal Fontan candidates with atrial arrhythmias or poor ventricular function, large numbers of patients with extracardiac conduits) must await the results of similar, careful studies in a wider spectrum of patients.  


Jenkins KJ, Gauvreau K, Newburger JW, Spray TL, Moller JH, Iessoni LI. Consensus-based method for risk adjustment for surgery for congenital heart disease. J Thorac Cardiovasc Surg 2002; 123:110-18.

 

An 11-member panel of pediatric cardiologists and cardiac surgeons placed congenital heart surgical procedures into 6 risk categories, based on clinical judgement. Data sets from the Pediatric Cardiac Care Consortium (PCCC) for the year 1996, as well as hospital discharge data from Illinois in 1994, Massachusetts in 1995, and California in 1995 were then reviewed. These data sets were used to refine the 6 risk categories. In-hospital mortality ranged from 0.3-0.4% in risk category 1, to 41-47% in risk category 6. Multivariable analysis showed that younger age, prematurity, and the presence of a major noncardiac structural anomaly added to the risk predicted by risk category alone.

 

¨         No method of risk adjustment for congenital heart disease is currently accepted. This report develops a system which groups operative procedures into 6 risk categories. This system was generated on the basis of consensus and clinical judgement, and was then adjusted by review of data from 2 large multi-institutional data sets. It should provide a useful tool for allowing meaningful comparisons of in-hospital mortality for groups of children undergoing congenital heart operations. At least one other such tool is being developed by the International Congenital Heart Surgery Nomenclature and Database Project (Maruszewski et al, Eur J Cardiothor Surg 2002; 21:47 -49). 


Serraf A, Piot JD, Belli E, Lacour-Gayet F, Touchot A, Roussin R, Zoghbi J, Bruniaux J, Planche C. Biventricular repair of transposition of the great arteries and unbalanced ventricles. J Thorac Cardiovasc Surg 2001; 122:1199-207.

 

Since 1984, 44 patients with transposition of the great arteries and unbalanced ventricles underwent biventricular repair, including an arterial switch procedure. 28/44 patients had a dominant right ventricle. Their median end-diastolic left ventricular volume was 15 ml/m2 (range 11-16); median long-axis ratio was 0.85 (range 0.7-0.9); median mitral valve diameter Z score was -1.2 (range -3.7 to -0.3). 1/28 patient, with an end-diastolic left ventricular volume  of 12, died early. By hospital discharge, median end-diastolic left ventricular volume increased to 25 (range 21-30). 1 patient had persistent pulmonary hypertension at follow-up and died 1 year after repair.

 

16/44 patients had a dominant left ventricle. All had at least one VSD, and 9/16 had aortic coarctation. Their median long-axis ratio was 0.6 (range 0.3-0.8); median tricuspid valve diameter Z score was -0.9 (range -3.3 to -0.5). 7/16 underwent a staged procedure; 9/16 underwent a single-stage procedure, 7/9 with a fenestrated VSD or ASD patch. The 2 patients who had single stage repair without a fenestrated intracardiac patch both died early. At 2 months after operation, median long-axis ratio increased to 0.8 (range 0.7-1.0); median tricuspid Z score increased to -0.2 (range -3 to 1.2).

 

¨                  Surgical decision-making in the infant with transposition and a hypoplastic ventricle can be difficult. This report gives some guidelines for deciding on biventricular repair. Patients with a hypoplastic left ventricle in the range examined generally do well with an arterial switch procedure, and demonstrate rapid increase in LV size by hospital discharge. Patients with a hypoplastic right ventricle (usually in the setting of VSD and aortic arch obstruction) are well managed by a single-stage repair, but this should include fenestration of the ASD closure. The optimal approach in patients with ventricular hypoplasia below the ranges seen in this study is less clear.


Caspi J, Pettitt TW, Fontenot EE, Stopa AR , Heck HA, Munfakh NA, Ferguson TB, Harrison LH.  The beneficial hemodynamic effects of selective patent vertical vein following repair of obstructed total anomalous pulmonary venous drainage in infants.  Eur J Cardiothorac Surg 2001; 20:830-4.

 

This study evaluates the hemodynamic effects of a patent vertical vein in patients who have undergone repair of total anomalous pulmonary venous drainage. 34 patients under 3 months of age underwent operation between 1993 and 2000. 22/34 patients (65%) had obstructed pulmonary venous drainage. The vertical vein was snared shut during operation. In the 22 patients with obstructed drainage, the snare was opened in the early postoperative period. Opening the vertical vein resulted in a fall in mean left atrial pressure (from 19 to 12 mmHg), a fall in mean pulmonary artery pressure (from 42 to 35 mmHg), and a rise in mean systemic blood pressure (from 46 to 60 mmHg). There were no operative deaths. Follow-up echocardiography demonstrated trivial or no flow through the vertical vein.

 

¨         Patients with total anomalous pulmonary venous return frequently have small, non-compliant left atria and ventricles. Their postoperative course may be marked by high left atrial pressure, and low cardiac output. Leaving the vertical vein patent in this setting has the theoretical advantage of providing a “pop-off” for the left atrium, thus decreasing left atrial pressure, and potentially pulmonary artery pressure. However, it would also be expected to decrease left ventricular filling, and create an atrial level left-to-right shunt, with increased right ventricular volume load,  pulmonary blood flow, and Qp:Qs. Whether this approach provides actual clinical advantages has been debated. This report provides data which suggests that hemodynamic status improves when the vertical vein is opened in the early postoperative period. The exact mechanism behind the improvement in systemic blood pressure is not clear. However, this report does add some hemodynamic data to an interesting clinical debate.   

 


Von Kodolitsch Y, Aydin MA, Koschyk DH, Loose R, Schalwat I, Karck M, Cremer J, Haverich A, Berger J, Meinertz T, Nienaber CA.  Predictors of aneurysmal formation after surgical correction of aortic coarctation.  J Am Coll Cardiol 2002; 39:617-624.

 

The goal of this study was to identify predictors of aneurysm formation after surgical correction of aortic coarctation.  Starting with a database of  patients with aortic aneurysms (from many different etiologies), 25 patients who had aortic aneurysm following coarctation repair were identified.  Of 25 aneurysms requiring surgery (mean 152 months after coarctation repair), 8 were located in the ascending aorta and 17 were at the site of the previous repair.  These were compared to 74 patients who had coarctation repair (without aortic aneurysm) from the same time period.  Local aneurysm was predicted by advanced age at time of initial repair (p=0.004) and patch graft technique (p<0.0005).  Aneurysm in the ascending aorta was associated with bicuspid aortic valve (p=0.02), advanced age at time of repair (p=0.04), and high preoperative peak systolic pressure gradient by univariate analysis, but was only associated with bicuspid aortic valve by multivariate analysis (p=0.015).  72% of patients with a postsurgical aneurysm had an operation at 13.5 years or more; 69% with no aneurysm had an operation at a younger age.

 

·                    This study helps guide clinicians caring for patients who underwent surgical repair of aortic coarctation.  It appears that aneurysm formation is associated with use of patch graft technique, with bicuspid aortic valve, and with late repair.  Because of the nature of this study (cases were identified from a database of aneurysms of the aorta from many causes), it is not possible to say what percentage of patients with coarctation repair developed aneurysms.  Other than this minor limitation, I found this a worthwhile and useful report.


Ohno T, Yuge T, Kariyazono H, Igarashi H, Joh-o K, Kinugawa N, Kusuhara K, Hara T.  Serum hepatocyte growth factor combined with vascular endothelial growth factor as a predictive indicator for the occurrence of coronary artery lesions in Kawasaki disease.  Eur J Pediatr 2002; 161:105-111.

 

To explore the possible use of serum hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) levels as predictive indicators for occurrence of coronary artery lesions ( CAL ) in Kawasaki disease (KD), levels were measured in 41 patients with KD and in 25 afebrile controls.  Serum HGF levels were higher in patients with KD than in controls (p<0.05).  Univariate analysis showed correlations between CAL and the following variables: duration of fever (p=0.018), serum C-reactive protein concentration (p=0.024), albumin concentration (p=0.009), serum VEGF level (p=0.009), and serum HGF level (p=0.055).  Multivariate analysis showed that serum HGF and VEGF levels and presence of edema were major risk factors for the occurrence of CAL .  The authors describe a new risk classification system using HGF level, VEGF level, and presence of edema, which showed a sensitivity of 100% and a specificity of 94.4% for identifying CAL .

 

·                    HGF and VEGF levels are not routine laboratory assays in most hospitals, and thus at the present time have limited use for clinicians managing patients with Kawasaki disease.  Nonetheless, I found this a fascinating study for several reasons.  First, because HGF and VEGF levels are elevated during the acute phase of KD, if this information could be obtained, it could help guide diagnosis, prognosis, and therapy of patients with KD at the time of the acute illness.  In addition, levels of HGF and VEGF could potentially be useful for monitoring various treatment modalities for KD, both for the individual patient as well as for a series of patients with KD,  possibly guiding therapy to reduce the incidence or severity of CAL .  Although this study did not address the issue, it would be interesting to know if elevated HGF and VEGF are present in other disease states, or are specific to KD.  If so, it would give added impetus for hospitals and laboratories to include measurement of these levels.


Engvall J, Nyström F.  Daytime ambulatory blood pressure correlates strongly with the echocardiographic diameter of aortic coarctation.  Scand Cardiovasc J 2001; 35:335-339.

 

The authors measured ambulatory and clinic blood pressure (BP) in 18 adults with coarctation of the aorta (14 corrected) and 36 controls, and measured the coarctation diameter using transesophageal echocardiography.  Systolic clinic and ambulatory BP levels were higher in patients than controls (clinic 146 vs. 119 mm, ambulatory 140 vs. 124 mm).  The relationship between BP and coarctation diameter was stronger for ambulatory daytime BP than clinic BP.  In surgically corrected patients, only the correlation between ambulatory systolic BP to coarctation diameter was statistically significant.

 

·                    There appears to be a strong correlation between ambulatory systolic BP and the diameter of uncorrected or corrected coarctation diameter.  The authors demonstrate that ambulatory systolic BP correlates more closely with coarctation diameter, suggesting that ambulatory BP measurements may provide important clinical information in addition to standard clinic BP measurements.


Wu MH, Wang JK, Lue HC.  Sudden death in patients with right isomerism (asplenism) after palliation.  J Pediatr 2002; 240:93-96.

 

To determine the risk of sudden death in patients with right atrial isomerism (asplenia) after palliation, 154 patients were identified.  The 1-year and 5-year survival was 72% and 50%, with 22 sudden deaths (defined as acute cardiovascular collapse from which death occurred within 24 hours), which included 14% of all patients studied.  Sudden death tended to occur in infancy or early childhood (mean 12 months, median 9 months).  Mechanisms were sudden tachyarrhythmia in 2, sudden cardiac but nontachyarrhythmic (sudden, severe cyanosis) in 15, and sudden noncardiac in 5 (fulminant sepsis with positive blood culture).  The incidence of sudden death decreased with age until 3 years of age.

 

·                    Because of the high morbidity and mortality in patients with asplenia, as well as the rarity of this lesion, I found this large study enlightening and clinically useful.  When counseling parents of children with asplenia, having specific information regarding the high chance of mortality (as well as morbidity) is important to include in the discussion. Knowledge of the mechanisms is interesting, and could help guide therapy for infants and young children with asplenia.


Greil GF, Powell AJ, Gildein HP, Geva T.  Gadolinium-enhanced three-dimensional magnetic resonance angiography of pulmonary and systemic venous anomalies.  J Am Coll Cardiol 2002; 39:355-341.

 

The goal of this study was to evaluate the diagnostic value of gadolinium-enhanced three-dimensional (3D) magnetic resonance angiography (MRA) in patients with congenital and acquired anomalies of the pulmonary and systemic veins.  61 patients were evaluated, including 37 with pulmonary venous anomalies, 17 with systemic venous anomalies, and 7 with pulmonary and systemic venous anomalies.  Compared with available diagnostic information by other modalities, all known or suspected venous anomalies were imaged by 3D MRA.  Following 3D MRA diagnoses, 10 interventional and 15 operations were performed.  In 74% of patients, 3D MRA either diagnosed previously unsuspected venous anomalies (28%) or added new clinically important information (46%).  The mechanism of pulmonary vein compression in 8 patients was determined by MRA but not by other imaging modalities.  Using a grading system for MRA image quality (1=nondiagnostic to 5=excellent), the average grade was 4.6 0.6.

 

·                    Although MRI has been shown in the past to be helpful for evaluation of pulmonary and systemic venous malformations, one limitation has been that traditional MRI techniques require relatively long scan times.  Because gadolinium-enhanced 3D MRA provides a much faster technique (studies typically require less than one minute for image acquisition), and the diagnostic information appears superior to traditional modalities such as echo or cardiac catheterization, it appears from this study that this technique should be the method of choice for evaluation of patients with suspected pulmonary or systemic venous anomalies in centers in which it is available.  I would suggest taking a look at the original paper for some lovely images.


Chang RKR, Klitzner TS.  Can regionalization decrease the number of deaths for children who undergo cardiac surgery?  A theoretical analysis.  Pediatrics 2002; 109:173-181.

 

To simulate the effects of regionalization on pediatric cardiac surgery, the authors assessed the impact of reducing the number of pediatric cardiac centers, using statewide hospital discharge data from California from 1995 to 1997, including all hospitals with 10 or more pediatric cardiac surgeries.  To simulate regionalization, the authors "closed" the hospital in a region with the lowest case volume, and redistributed patients from this hospital to the nearest remaining hospitals.  The number of in-hospital deaths was then recalculated using the original mortality rate of each remaining hospital multiplied by its new case volume.  A multivariate logistic regression was conducted to determine the odds ratios of mortality of various types of surgery, which was used to adjust for the case-mix of the hospitals.  6592 children underwent cardiac surgeries during the study years, with 352 in-hospital deaths (5.34% mortality).  High surgical volume was associated with a low mortality rate.  Adjusting for hospital case-mix, 41 deaths could have been avoided if all patients from low-volume hospitals (less than 70 cases per year) had been referred, and 83 deaths could have been avoided if all patients from medium-volume (70-170 cases per year) and low-volume hospitals had been referred (overall mortality would have decreased to 4.08%).  The average travel distance was 45.4 miles, which increased to 58.1 miles if all surgeries were referred to high-volume hospitals.

 

·                    This interesting study makes a striking and convincing case in favor of regionalization of pediatric cardiac surgery, using a refined simulation model to assess the impact of regionalization on potential avoidable deaths from such surgery.  Although in this study, regionalization would increase the travel distance for patients (presumably increasing travel costs and decreasing convenience), the apparent dramatic improvement in patient mortality might well offset the cost and inconvenience, if these results are confirmed in future studies.  Certainly similar analyses by other groups would be welcome, and if similar conclusions are reached, a strong argument in favor of regionalization can be made.

 

 

September/October 2002 issue [23.5]

Turrentine MW, McCarthey RP, Vijay P, McConnell KW, Brown J.  PTFE monocusp valve reconstruction of the right ventricular outflow tract. Ann Thorac Surg 2002;73:871-80.

 

From 1990 to 1999, 158 patients underwent operations involving reconstruction of the right ventricular outflow tract. From 1990 to 1994, 43 patients received nonvalved transannular patches; from 1994 to 1999, 115 received PTFE (Gore-Tex, 0.1 mm thick) monocusp valves. The mean age in the transannular patch group was 3 years, and in the monocusp group was 4 years. The outcomes of the 2 groups were retrospectively compared. Perioperative complications, including mortality, did not differ between the 2 groups. The monocusp group had a shorter duration of ICU stay (3.6 vs. 5.8 days, P = 0.03), but there was no difference in mean hospital stay. Over a mean follow-up of 2.6 years, mean pulmonary regurgitation increased to mild-moderate in the monocusp group, but remained significantly less than the transannular patch group.

 

¨         Previous studies of the use of pericardial monocusp valves for right ventricular outflow tract reconstruction have shown early competence, but late deterioration with insufficiency.  This large experience with PTFE membrane monocusp valves nicely demonstrates early competence, and no late failure from stenosis. Some patients maintain competence out to 2.5 years, although there is decreasing competence over time. While ICU stay was lower in the monocusp group, this difference could have been accounted for by the monocusp patients being operated more recently. The questions of whether monocusp reconstruction reduces early postoperative right ventricular failure (diastolic dysfunction, characterized by elevated right atrial pressure, right-to-left shunting via a PFO, tachycardia, low cardiac output, and increased inotrope requirement) and/or late right ventricular dilation and failure, remain open.   


Pinkney KA, Minich L, Tani LY, DiRusso GB, Veasy G, McGough EC, Hawkins JA.  Current results with intraaortic balloon pumping in  infants and children. Ann Thorac Surg 2002;73:887-91.

 

29 children underwent placement of an intraaortic balloon pump between 1988 and 2000. This approach was used in the absence of  ventricular assist device, or ECMO programs.  Indications were postoperative failure in 16, medical heart failure in 6, and as a bridge to transplant in 7. The balloons were placed via a short PTFE graft attached to the common femoral artery. Mean age was 5.7 years, with a range of 1.7 months to 18 years. 8 patients were less than 1 year of age. Duration of therapy ranged from 3 hours to 10 days. Overall survival was 62%.  Since 1994, M-mode echocardiography, rather than electrocardiography, was used, for balloon timing.

 

¨         This report details current techniques, indications, and results of intraaortic balloon pumping in children. It demonstrates that this approach can be successful, with few complications. As the authors point out, an intraaortic balloon pump is unlikely to be effective in children with cardiac failure due to biventricular dysfunction, or pulmonary hypertension. However, this experience may  increase consideration of a balloon pump in children with isolated left ventricular failure, even in institutions with the availability of a ventricular assist device, or ECMO.  


Odegard KC, McGowan FX, Dinardo JA, Castro RA, Zurakowski D, Connor CM, Hansen DD, Neufeld EJ, del Nido PJ, Laussen PC. Coagulation abnormalities in patients with single-ventricle physiology precede the Fontan procedure. J Thorac Cardiovasc Surg 2002;123:459-65.

 

Coagulation factors were assayed in 36 infants with functional single ventricles immediately prior to undergoing a bidirectional Glenn shunt. Infants without cardiac disease provided age-matched control values. The pre-Glenn infants were found to have significantly decreased levels of protein C; factors II, V, VII, IX, and X; plasminogen; fibrinogen; and antithrombin III. The only significant predictor of multiple coagulation factor abnormalities was decreased ventricular function. 

 

¨         A variety of coagulation abnormalities have been previously reported in patients who have undergone a Fontan operation. These abnormalities have been attributed to the “Fontan physiology”, and implicated in thromboembolic complications. This study demonstrates that patients with single ventricle physiology have a high incidence of abnormalities in both procoagulant and anticoagulant factors compared to age-matched controls. These abnormalities are present well before the Fontan operation, and even before the bidirectional Glenn. The causes as well as the clinical significance of these abnormalities require further study, and will be of great interest.

 


Ackerman MJ, Khositseth A, Tester DJ, Hejlik JB, Shen WK, Porter CJ.  Epinephrine-induced QT interval prolongation: A gene-specific paradoxical response in congenital long QT syndrome.  Mayo Clin Proc 2002; 77:413-421.

 

To determine the effect of epinephrine on the QT interval in patients with genotyped long QT syndrome (LQTS), 37 such patients (age 10 to 53 years, mean 27) and 27 controls were studied.  12 lead ECGs were obtained at baseline and during increasing doses of epinephrine (0.05, 0.1, 0.2, and 0.3 micrograms per kg per minute).  Resting HR and chronotropic response to epinephrine was similar in patients and controls.  Although the mean baseline QTC was greater in LQTS patients than in controls (50068 ms vs. 43619 ms), 9 of 19 (47%) of KVLQT1-genotyped LQT1 patients had a non-diagnostic resting QTC (<460 ms), and 11 of 27 (41%) of controls had a resting QTC higher than 440 ms.  During epinephrine infusion, every LQT1 patient had prolongation of the QT interval (paradoxical response), while controls and patients with LQT2 or LQT3 tended to have shortened QT intervals (p<0.001).  While 6 of 27 controls had lengthening of their QT intervals (>30 ms) during high-dose epinephrine, low-dose epinephrine completely discriminated LQT1 patients from controls (change in QT +82 ms vs. –7 ms; p<0.001).  Epinephrine-triggered nonsustained ventricular tachycardia occurred in 2 patients with LQTS and in one control.  The authors conclude that epinephrine provocation may help unmask some patients with concealed LQTS and strategically direct molecular genetic testing.

 

·                    Because of the significant morbidity and mortality in patients with LQTS, it is important to make an accurate diagnosis of this disorder.  Prolongation of the corrected QT interval on a resting 12-lead ECG is the cornerstone of the diagnosis of congenital LQTS, yet many patients with LQTS have an equivocal or borderline QTC.  Although exercise testing and drug provocation have been suggested to enhance the diagnostic accuracy in LQTS, limited data are available studying these modalities.  This report provides interesting information, and suggests that low-dose epinephrine administration may be helpful for evaluation of patients with this rare but potentially life-threatening condition.


El Habbal MH, Mahoney CO.  QT interval in children with sensory neural hearing loss.  PACE 2002; 25:435-439.

 

Although the long QT syndrome was first described in children with congenital sensory neural hearing loss (SNHL), the risk for patients with SNHL to have LQTS is unknown.  The authors studied 52 patients with SNHL (median age 8 years) and 63 controls (median age 10 years), obtaining ECG, a 24-hour ambulatory ECG (with power spectral analysis of heart rate variability, expressed as high frequency to low frequency ratio), and 2D echo.  The QTC was longer in patients with SNHL (median 417 ms, range 384-490 ms, p<0.001).  QT dispersions in SNHL were higher than controls (p<0.001).  8 of 52 patients with SNHL had a history of dizziness with exertion; all had QTC  440 ms.

 

·                    Long QT syndrome in patients with congenital SNHL was first described by Jervell and Lange-Nielsen.  Recent reports have shown that abnormalities in potassium ion channels in the inner ear and in cardiac muscle may be involved in causing hearing loss and the cardiac abnormalities.  This study shows that patients with SNHL have an increased QT interval, and suggests that all patients with SNHL should have evaluation for long QT syndrome.


Rubin LJ, Badesch DB, Barst RB, Galiè N, Black CM, Keogh A, Pulido T, Frost A, Roux S, Leconte I, Landzberg M, Simonneau G.  Bosentan therapy for pulmonary arterial hypertension.  N Engl J Med 2002; 346:896-903.

 

In this double-blind, randomized, placebo-controlled study, 213 patients with pulmonary arterial hypertension received placebo or 6.25 mg of bosentan (an oral endothelin antagonist) twice daily for 4 weeks, followed by two doses of bosentan (125 mg or 250 mg twice daily) for at least 12 weeks.  At week 16, patients treated with bosentan had improved six-minute walking distance (mean difference vs. placebo 44 meters, p<0.001).  Patients treated with bosentan also had an improved Borg dyspnea index, improved WHO functional class, and increased time to clinical worsening.  The authors conclude that oral bosentan is an effective approach to therapy for pulmonary arterial hypertension.

 

·                    Because of the significant morbidity and mortality associated with pulmonary arterial hypertension, several reports have explored a variety of treatment options for these patients.  Previously, limited success was found using oral agents such as anticoagulation therapy and calcium-channel blockers.  More recently, beneficial effects have been noted with intravenous continuous epoprostenol (prostacyclin), though this approach has some drawbacks.  Recently, limited reports have become available exploring the use of epoprostenol analogues that can be inhaled (such as iloprost) or taken orally (such as beraprost; see next review).  Endothelin-1 is a potent vasoconstrictor and smooth-muscle mitogen; there is increasing evidence that it has a pathologic role in pulmonary arterial hypertension, and that blockage of endothelin receptors may be beneficial.  In a recent study of WHO class III patients with pulmonary arterial hypertension, patients receiving 125 mg BID of bosentan for 12 weeks had improved exercise capacity and cardiopulmonary hemodynamics.  Although the current study did not measure hemodynamic data, this is an important study for several reasons.  A much larger number of patients were studied, in a double-blind, placebo-controlled design, and WHO functional class III and IV were included.  Based on this excellent study, it appears that bosentan therapy will prove useful for treating this challenging group of patients.


Galiè N, Humbert M, Vachiéry JL, Vizza CD, Kneussl M, Manes A, Sitbon O, Torbicki A, Delcroix M, Naeije R, Hoeper M, Chaouat A, Morand S, Besse B, Simonneau G.  Effects of beraprost sodium, an oral prostacyclin analogue, in patients with pulmonary arterial hypertension: A randomized, double-blind, placebo-controlled trial.  J Am Coll Cardiol 2002; 39:1496-1502.

 

In this double-blind and placebo-controlled study, 130 patients with pulmonary arterial hypertension (functional classification III and IV) were randomized to placebo or to the maximal tolerated dose of beraprost, an oral analogue of epoprostenol (prostacyclin).  Patients treated with beraprost had improved exercise capacity and symptoms.  The difference between treatment groups in the mean change of 6 minute walking distance at week 12 was 25 meters, and was 46.1 meters in patients with primary pulmonary hypertension.  The Borg dyspnea index was significantly improved in patients receiving beraprost (p<0.009).  Cardiopulmonary hemodynamics and NYHA functional class had no statistically significant changes.

 

·                    A very nice study which appears to show that beraprost is another useful oral agent for treating patients with pulmonary arterial hypertension.  A useful feature of this study is that exercise capacity and hemodynamics were measured.  Although no statistically significant changes in cardiopulmonary hemodynamics were seen, there appeared to be a trend toward decreased pulmonary vascular resistance in patients treated with beraprost.


Gabriel HM, Heger M, Innerhofer P, Zehetgruber M, Mundigler G, Wimmer M, Maurer G, Baumgartner H.  Long-term outcome of patients with ventricular septal defect considered not to require surgical closure during childhood.  J Am Coll Cardiol 2002; 39:1066-1071.

 

This study reports findings in 229 consecutive patients from an adult congenital heart clinic with a ventricular septal defect (VSD) considered too small to require surgery during childhood (defined by normal pulmonary artery pressure, QP:QS<2:1, pulmonary vascular resistance  200 dynesscm-5, no VSD-related aortic regurgitation, no symptoms and no additional hemodynamically relevant heart defect).  Physical exam, ECG, and echo were performed in all patients in one- to three-year intervals.  Follow-up was obtained in 222 patients (97%).  14 (6%) had spontaneous VSD closure.  No patients died, 4 (1.8%) had an episode of endocarditis (of whom two required aortic valve replacement), and one patient had surgical closure for hemodynamic reasons.  118 patients (enrolled between 1993 and 1996) were followed prospectively for 7.41.2 years.  Among these patients, event-free survival (end-points death, endocarditis, or heart surgery) was 99.1% at three years, 96.5% at six years, and 95.5% at eight years.  At last visit, 94.6% of all patients studied were symptom free.  Left ventricular size by echo was normal in 198 (89%) of patients, borderline in 23 and enlarged in only one.  None had LV dysfunction, and pulmonary artery pressure was normal in all patients.  Aortic regurgitation was present in 12 (trace in 7, mild in 5), 3 had bicuspid aortic valve, one had moderate aortic stenosis, and 2 had aortic valve replacement.  Mean exercise capacity was 92% of expected, and 87% of patients had no arrhythmias on Holter monitoring.  The authors conclude that outcome in most patients with a small VSD is good, and that most such patients do not require surgical closure.

 

·                    Although patients with small VSDs have historically been managed conservatively, some recent reports have suggested that a significant percentage may develop serious problems during adult life.  This large adult series seems to support conservative management for such patients.  In my opinion, the jury is still out on this issue, and further detailed studies will provide helpful information.


Thomson JDR, Aburawi EH, Watterson KG, Van Doorn C, Gibbs JL.  Surgical and transcatheter (Amplatzer) closure of atrial septal defects: A prospective comparison of results and cost.  Heart 2002; 87:466-469.

 

The goal of this prospective study was to compare effectiveness, complications and cost of the Amplatzer vs. surgical atrial septal defect (ASD) closure.  In 43 consecutive patients, Amplatzer closure was successful in 24 of 27 (89%) patients, while surgical closure was successful in all 19 cases.  Cardiac complications affecting management occurred in three (11%) of the Amplatzer group (two procedural failures, one device embolization) and 9 of 24 (21%) surgical patients (one pericardial pain, one pericardial effusion requiring drainage, one with anemia and incidental pericardial effusion, and one with incidental pericardial effusion).  Complications not affecting management were present in 5 of 19 surgical patients.  Both hospital stay and home convalescent times were shorter after Amplatzer closure (median hospital stay: Amplatzer one day, surgery six days; median convalescent time: Amplatzer two weeks, surgery 5.5 weeks).  Median cost was similar for both groups (Amplatzer £5375, surgical £5412).

 

·                    Since many of the first successful open heart surgeries were performed on patients with ASDs, there is now a nearly 50-year experience with this technique.  Although the Amplatzer device has a shorter track record (meaning it is impossible at the present time to predict the 50 year follow-up), based on the short-term results, it appears to be a reasonable alternative to surgery.  This study shows a nice example of "head-to-head" competition.

 

 

November/December 2002 issue [23.6]

Duncan BW.  Mechanical circulatory support for infants and children with cardiac disease. Ann Thorac Surg 2002;73:1670-7.

 

This review article examines: 1. The relative attributes of extracorporeal membrane oxygenation (ECMO) and ventricular assist devices (VAD), including effects on ventricular recovery and long-term outcome; 2. Innovative use of ECMO for rapid resuscitation following cardiac arrest and for treatment of acute fulminant myocarditis; 3. The current state-of-the-art in pediatric VAD’s, including centrifugal, and pulsatile, paracorporeal systems. 

 

¨         The indications for and use of mechanical circulatory support in children are increasing.  This article provides an excellent, concise review of current status and future directions in this area.    


Backer CL, Mavroudis C.  Surgical management of aortopulmonary window: a 40-year experience. Eur J Cardiothor Surg 2002;21:773-9.

 

22 patients underwent repair of aortopulmonary window at a single institution between 1961 and 2001.  Important associated lesions were common and included interrupted aortic arch in 4, origin of the right pulmonary artery from the aorta in 4, ventricular septal defect in 3, tetralogy of Fallot in 1 and transposition of the great arteries in 1. Operative technique evolved over the 40 years. Early approaches included ligation without cardiopulmonary bypass (2 patients), division between clamps (1 patient), and division on cardiopulmonary bypass with primary aortic closure (10 patients). The most recent 6 patients had open transaortic closure with a patch of Gore-Tex, at a mean age of 0.7 years. There were 5 early and 1 late deaths. The 6 recent patients had no mortality, and demonstrated normal pulmonary artery and aortic growth by echocardiography up to 8 years postoperatively. 

 

¨         This report provides an interesting look at the evolving surgical approach to a rare congenital heart defect over a 40-year period.  As in most centers, the current approach consists of early complete repair, including associated defects, at the time of diagnosis. Transaortic patch closure is one of several specific techniques, which provides good results.


Hraska V, Kantorova A, Kunovsky P, Haviar D. Intermediate results with correction of tetralogy of Fallot with absent pulmonary valve using a new approach. Eur J Cardiothor Surg 2002;21:711-15.

 

Six patients underwent primary repair of tetralogy with absent pulmonary valve between 1998 and 2000. The operative approach in all included translocation of the pulmonary arteries anterior to the aorta (Lecompte maneuver). A competent pulmonary valve was also placed in 3 patients, and pulmonary artery plication performed in 3 patients. Median age was 37 days (range 14-256 days); 3 patients were neonates. None required preoperative assisted ventilation. There was no mortality. Postoperative mechanical ventilation ranged from 2-13 days. During a median follow-up of 27 months, one patient required reoperation for placement of a pulmonary valved conduit. Postoperative CT scans showed no tracheal or bronchial compression.

 

¨                  This surgical approach to tetralogy with absent pulmonary valve includes the novel step of placing the pulmonary arteries anterior to the aorta. This step is aimed at removing the dilated pulmonary vessels from the airways, and relieving airway compression. The results have been good, and the approach clearly has merit. None of the 6 patients in this report was sufficiently symptomatic to require preoperative intubation. It would be of great interest to know whether this approach is effective in the severely symptomatic neonate with airway compression and malacia requiring preoperative ventilation or ECMO.


Pizarro C, Davis DA, Galantowicz ME, Munro H, Gidding SS, Norwood WI . Stage I palliation for hypoplastic left heart syndrome in low birth weight neonates: can we justify it? Eur J Cardiothor Surg 2002;21:716-20.

 

Between 1998 and 2000, 20 consecutive neonates weighing < 2.5 kg underwent stage I palliation for HLHS or a variant.  Weight ranged from 1.1-2.5 kg, with 9 patients < 2 kg.  10 patients were also premature (< 35 weeks gestation).  Mechanical extracorporeal support was used perioperatively in 10 patients. Early mortality was 9/20 (45%). Restrictive pulmonary venous drainage was a risk factor for mortality. Median hospital stay for survivors was 16 days (range 8-85 days). At a mean follow-up of 22 months, there was 1 death at 4 months;10 patients have undergone stage 2, with 4 completing a Fontan procedure.   

 

¨         Low birth weight neonates with HLHS have increased early surgical risk, as do neonates with other congenital heart defects undergoing biventricular repair. However, intermediate survival, and subsequent progression to cavopulmonary connection are reasonable.  The authors argue that that low birth weight alone should not be regarded as a contraindication to surgical palliation.


Forbess JM, Visconti KJ, Bellinger DC, Howe RJ, Jonas RA. Neurodevelopmental outcomes after biventricular repair of congenital heart defects. J Thorac Cardiovasc Surg 2002;123:631-9.

 

Detailed neurodevelopmental tests of 69 patients who had undergone biventricular repairs were carried out at 5 years of age. The 2 most common anatomic diagnoses were tetralogy of Fallot (in 29%), and ventricular septal defect (in 28%). Patients with transposition were excluded, as their information had been included in a previous study. The median age at repair was 91 days. Deep hypothermic circulatory arrest (mean duration 33 minutes, range 2-59 minutes) was used in 35/69 patients (51%).  Mean IQ (full-scale, performance and verbal) was within 1 standard deviation of the population norm of 100 (mean full-scale IQ = 97).  After adjustment for socioeconomic status, full-scale and performance IQ, as well as some subtests of visual-motor and fine motor abilities were lower among patients with > 39 minutes of circulatory arrest.

 

¨         Intellectual development following repair of congenital heart defects is an area of active investigation. This report contains data from an ongoing registry of neuropsychologic testing at Boston Children’s Hospital. On average, IQ’s of patients undergoing biventricular repair of congenital heart defects other than transposition were within the reference range.  The only operative variable associated with lower scores in this extensive neuropsychologic testing was a hypothermic circulatory arrest time exceeding 39 minutes.

 

 

2003 Issues:
January/February 2003 issue [24.1]

Knott-Craig CJ, Overholt ED, Ward KE, Ringewald JM, Baker SS, Razook JD.  Repair of Ebstein’s anomaly in the symptomatic neonate: an evolution of technique with 7-year follow-up. Ann Thorac Surg 2002;73:1786-93.

 

Between 1994 and 2001, 8 infants (including 6 neonates) underwent biventricular repair of Ebstein’s anomaly or severe tricuspid valve dysplasia. One 2 month old had undergone previous tricuspid valve closure and shunt placement (Starnes operation). She underwent tricuspid valve replacement with a St. Jude valve. The remaining 7 patients had severe tricuspid regurgitation, cardiothoracic ratio >0.85, and ventilator-dependence. Echocardiography severity score (Celermajer) was grade 4/4 in 6/7 patients. Operation included tricuspid valve repair, right atrial reduction, and partial ASD closure leaving a 3mm fenestration. There was one operative death. The 7 surviving patients are in functional class 1. Tricuspid insufficiency is mild in 4, and mild-moderate in 2. The oldest 3 patients are now 7 years old.

 

¨         Several approaches to the repair of Ebstein’s anomaly have good results in children beyond infancy. However, they have not generally been applied in neonates, many of whom have been treated by conversion to single ventricle palliation. This article demonstrates that biventricular repair, including tricuspid valve repair, is feasible in severely ill neonates-an impressive achievement. The article also gives excellent details on the techniques of tricuspid valve repair.   


Backer CL, Hillman N, Mavroudis C, Holinger LD.  Resection of Kommerell’s diverticulum and left subclavian artery transfer for recurrent symptoms after vascular ring division. Eur J Cardiothor Surg 2002;22:64-9.

 

Eight children were treated for recurrent symptoms (either respiratory or dysphagia) following a previous vascular ring division. All had a right aortic arch, Kommerell’s diverticulum, and left ligamentum. They had been previously treated by division of the ligamentum, leaving the Kommerell’s diverticulum in place. The time since initial operation ranged from 2.5 –13 years. All underwent reoperation via left thoracotomy, and resection of the diverticulum. In 2, the left subclavian artery originated from an anterior innominate artery (mirror-image branching) and was left in place. In 6, there was a retroesophageal left subclavian: 1 underwent division of the left subclavian;  the remaining 5 had reimplantation of the left subclavian into the left carotid artery. All patients had relief of tracheal compression verified by bronchoscopy, and resolution of their symptoms.   

 

¨         This paper demonstrates that a Kommerell’s diverticulum can cause symptoms following vascular ring division, and details a successful surgical approach to the problem. The incidence of recurrent symptoms among all patients who have a diverticulum left in place at their initial vascular ring division is not known. The authors have now altered their primary approach in patients with a right aortic arch and significant Kommerell’s diverticulum, adding diverticulum resection and left subclavian artery transfer to ligamentum division.


Wells WJ, Arroyo H, Bremner RM, Wood J, Starnes VA. Homograft conduit failure in infants is not due to somatic outgrowth. J Thorac Cardiovasc Surg 2002;124:88-96.

 

The aim of this paper was to identify reasons for failure of right ventricular outflow tract homograft conduits. 40 patients underwent homograft replacement from 1996 to 2000. Their median age at initial homograft placement was 8 months. The median time to conduit replacement was 5 years. Outgrowth of the conduit was examined by comparing the original conduit diameter to each patient’s expected pulmonary valve diameter at the time of reoperation. Only 3 patients had a conduit whose original size was more than 2 standard deviations below their normal pulmonary valve diameter (i.e. a Z value < -2). Conduit failure was judged to be due to shrinkage in 53% (generally at the valvular annulus), distal anastomotic stenosis in 10%, conduit kinking in 8%, sternal compression in 8%, and somatic outgrowth alone in 8%. The average decrease in conduit diameter from implantation to replacement was 47% (range 28-73%).

 

¨         Many groups have identified smaller homograft size, smaller patient size, and younger patient age as risk factors for failure of homograft conduits in the right ventricular outflow tract. The natural assumption is that such failures are due to somatic outgrowth of the conduit. This study nicely demonstrates that isolated somatic outgrowth is actually quite rare, while homograft shrinkage and distortion are common. Therapeutic implications include operative attention to homograft positioning, avoiding conduit over-sizing, and development of alternatives less susceptible to shrinkage (perhaps decellularized homografts, or tissue-engineered conduits).   


Lindberg L, Olsson AK , Jogi P, Jonmarker C. How common is severe pulmonary hypertension after pediatric cardiac surgery? J Thorac Cardiovasc Surg 2002;123:1155-63.

 

Data was examined from 1349 children younger than 18 years who underwent cardiac operations between 1994 and 1998 at the University Hospital of Lund. 164 (12%) were neonates, and 511 (38%) infants. Postoperative pulmonary hypertension was identified directly from pulmonary artery catheters, or by examining the records of patients with suggestive clinical criteria (mechanical ventilation for more than 4 days, operative death). Severe pulmonary hypertension was defined as a pulmonary artery pressure at least equal to systemic. Severe pulmonary hypertension was seen in 27 patients (2%). Their median age was 4 months; only 4 were older than 1 year. Among these 27, 2 (7%) died within 30 days. 5/27 were treated with nitric oxide. Severe pulmonary hypertension was most common after repair of complete atrioventricular septal defects (12/85 patients, 14%), and in children with Down syndrome (13/131, 10%).

 

¨         This paper documents that in the current practice of pediatric heart surgery, postoperative severe pulmonary hypertension is uncommon. This is due to a number of factors, including corrective surgery in younger children. However, clinically important pulmonary hypertension was still seen, particularly in patients with atrioventricular septal defect, Down syndrome, or pulmonary venous obstruction.    


Gaynor JW, Mahle WT, Cohen MI, Ittenbach RF, DeCampli WM, Steven JM, Nicolson SC, Spray TL. Risk factors for mortality after the Norwood procedure.  Eur J Cardiothor Surg 2002;22:82-89.

 

From 1998-2001, 158 underwent patients underwent a Norwood procedure. 102 had hypoplastic left heart syndrome, 56 had other forms of functional single ventricle with systemic outflow tract obstruction. Hospital survival was 77%; 78% for HLHS and 75% for non-HLHS.  By multivariable analysis, low birth weight, associated cardiac anomalies (including atrioventricular valve regurgitation and anomalous or obstructed pulmonary venous return), and total support time (cardiopulmonary bypass plus circulatory arrest time) were significantly associated with operative mortality. Prenatal diagnosis did not decrease mortality risk. Hospital survival was 88% for patients weighing > 2.5 kg with no associated anomalies. Overall actuarial survival at 1 year was 66%. Associated cardiac anomalies, extra-cardiac anomalies, and genetic syndromes were associated with worse survival at 1 year.

 

¨         This report examines predictors of mortality in a large, recent cohort of patients undergoing the Norwood procedure at Children’s Hospital of Philadelphia . It demonstrates continuing improvement in outcomes, despite application of the operation to a heterogeneous group of patients, many of whom have one or more risk factors for mortality. A challenge remains to identify changes in management strategy which might decrease risk to that of other heart defects requiring neonatal surgery.

 

 

Bruce, CJ, O’Leary, P, Hagler, DJ, Seward, JB, Cabalka , AK .   Miniaturized Transesophageal Echocardiography in Newborn Infants.  J Am Soc Echocardiogr 2002;15:791-7.

 

The authors evaluated whether a miniaturized transesophageal echocardiography (TEE) probe (5.5  to 10 MHz, phased-array, single longitudinal plane transducer mounted on a 3.3mm diameter catheter designed for intracardiac use)  could define clinically relevant anatomy in 17 infants less than 6 kg.  Twenty-two studies were performed in 17 infants (2.1 to 5.6 kg) without complication.  Twenty of  the twenty-two studies were diagnostic.  Biplane TEE was not possible in 13 studies.  The lack of horizontal plane imaging with miniaturized TEE made evaluation difficult in patients with atrioventricular septal defect. 

 

·                      Although TEE provides useful information for evaluation of children with congenital heart disease, its use in very small infants has been limited because of the relatively large probe size (9.1 to 9.5mm diameter tip with 8mm diameter shaft).  This nice study shows that a much smaller probe, designed primarily for intracardiac use, can also provide useful information for most patients with significant congenital heart disease.


Limperopoulos C, Majnemer A, Shevel MI, Roblicek C, Rosenblatt B, Tchervenkov C, Darwish, HZ.  Predictors of developmental disabilities after open heart surgery in young children with congenital heart defects.  J Pediatr 2002;141:51-8.

 

131 infants less than 2 years of age requiring open heart surgery were recruited prospectively.  Subjects were assessed at the time of surgery and 12-18 months later with standard developmental assessments and formal neurological examinations.  Mean age at follow-up testing was 19.1 + 6.6 months.  41% had abnormal neurological examinations.   42% had gross and/or fine motor delays, and 23% had global developmental delay.  Risk factors for persistent developmental deficits included preoperative and acute postoperative neurodevelopmental status and microcephaly , type of heart lesion, length of deep hypothermic circulatory arrest, age at surgery, and days in the intensive care unit.  The authors conclude that the cause of these deficits is multifactorial and includes brain injury before, during, and after heart surgery.

 

·                      In this relatively large study, follow-up neurodevelopmental examinations were performed on infants undergoing open-heart surgery (the perioperative neurologic findings had previously been reported by the authors).  I found it interesting not only how common neurodevelopmental problems were in this group, but also the multifactorial nature of these problems.  This would suggest that future improvements in neurodevelopmental outcomes might come from addressing preoperative, operative and postoperative factors.    


Beauchesne LM, Warnes CA, Connolly HM, Ammash NM, Tajik AJ, Danielson GK.   Outcome of the unoperated adult who presents with congenitally corrected transposition of the great arteries.  J Am Coll Cardiol 2002;40:285-90.

 

In order to determine the presentation and outcome of the unoperated adult with congenitally corrected transposition of the great arteries (CTGA), the records of all unoperated patients > 18 years of age were evaluated.  Forty-four patients aged 20 to 79 years (mean 44) were followed for up to 144 months.  In 29 (66%), the correct diagnosis was made after 18 years of age.  The diagnosis was missed in seven of these in a prior cardiology consultation, despite cardiac imaging.  Systemic atrioventricular valve (SAVV) regurgitation  of grade > 3/4 was present in 26 patients (59%).  Thirty (68%) had surgery including SAVV replacement in all, with no early mortality.  Preoperatively , this subset had poor function of the systemic ventricle and had advanced symptoms.  The ejection fraction decreased after surgery from 40% to 34% and four patients (13%) eventually required transplantation.

 

·                      This study shows that patients with CTGA are often misdiagnosed in adulthood (as well as during childhood).  Not surprisingly, poor function of the systemic ventricle  (morphologic right ventricle) is a common problem for these patients.  Because this challenging lesion is also relatively uncommon, I found this study useful, despite its retrospective nature and relatively small numbers.


Deal BJ, Mavroudis C, Backer CL, Buck SH, Johnsrude C.  Comparison of anatomic isthmus block with the modified right atrial maze procedure for late atrial tachycardia in Fontan patients.    Circulation. 2002;106:575-579.

 

In this study, 23 patients with late atrial reentry tachycardia (AT) who underwent Fontan revision had surgical arrhythmia ablation using cryoablation of the inferomedial right atrium (RA) (Group 1, n=8) and a modified RA maze procedure (Group 2, n=15).  At postoperative electrophysiology study, AT was inducible in 62% of Group 1 patients, but only in 7% of Group 2 patients (P < 0.02).  With mean follow-up of 43 months, 5 of 8 patients in Group 1 experienced AT recurrence versus none in Group 2 (P < 0.001).  

 

·                      Because of the high incidence of arrhythmias in Fontan patients and the challenge of treating these medically, new therapies that reduce arrhythmias for these patients are welcome.  Although the modified RA maze might not be appropriate for patients who do not require surgery, in patients with AT who require surgical revision of a Fontan the modified RA maze appears to be an excellent option with low morbidity and mortality.


Salbe AD, Weyer C, Lindsay RS, Ravussin E, Tataranni PA.   Assessing risk factors for obesity between childhood and adolescence: I. birth weight, childhood adiposity, parental obesity, insulin, and leptin.  Pediatrics 2002;110:299-306.

 

To assess the effects of body weight, body composition, parental obesity, and metabolic variables on the development of obesity in Native American children with a high propensity for obesity, 138 Pima Indian children (65 boys and 73 girls) were studied at 5 and 10 years of age.  The study population were heavier/or fatter than an age- and gender-based reference population.  All anthropometric and metabolic variables tracked strongly from 5 to 10 years of age (r > 0.70).  The most significant determinant of percentage of body fat at 10 years of age was percentage of body fat at 5 years of age (R2 = 0.53). The combined effect of high maternal body mass index , elevated fasting plasma leptin concentrations, and low fasting insulin concentrations at baseline explained only an additional 4% of the total variance in adiposity at follow-up. 

 

As the authors discuss in this paper, these results suggest that strategies to prevent childhood obesity must be initiated at a very early age.  It appears that, perhaps not surprisingly, chubby 5-year olds will continue to be chubby during childhood (and presumably beyond childhood), unless someone or something intervenes. 

 

 

 

March/April 2003 issue [24.2]

Margossian RE, Solowiejczyk D, Bourlon F, Apfel H, Gersony WM, Hordof AJ, Quaegebeur J. Septation of the single ventricle: revisited. J Thorac Cardiovasc Surg 2002;124:442-47.

 

Over the period 1990-1999, 11 patients entered a protocol for septation of a single ventricle. 9 of the 11 had double-inlet left ventricle. 6 patients had septation in 1 stage, at a median age of 2 years. 5 patients had the first stage of a planned 2-stage septation, at a median age of 7 months (partial septation with pulmonary artery banding). Eight of the 11 patients (73%) survived; seven of the 8 survivors have undergone complete septation. Complications included complete heart block in 1, and significant residual VSD in 1. Left ventricular function by echocardiography is normal in all patients. 

 

¨         Septation of a single ventricle into 2 functioning ventricles provides an alternative to the Fontan operation. This alternative has been rarely used, due to previously unacceptable morbidity and mortality. This report provides a recent experience for comparison to the extensively documented experience with the Fontan procedure. It recommends limiting septation to patients with a morphologic left ventricle, a large, volume-loaded heart, 2 well-functioning atrioventricular valves, and absence of severe outlet tract obstruction.


Mitchell MB, Campbell DN, Bishop DA, Mackenzie T, Clarke DR. Surgical options and results of repeated aortic root replacement for failed aortic allografts placed in childhood. J Thorac Cardiovasc Surg 2002;124:459-70.

 

From 1986 through 2001, 23 children underwent 25 reoperations for failure of a cryopreserved aortic allograft in the aortic position.  The mean age at reoperation was 12 years, and the mean interval to reoperation 6 years. Significant allograft insufficiency was present in 24 of the 25 cases. 4 of the resternotomies were complicated by cardiac injury. Extensive allograft calcification required complete excision and repeat replacement of the entire aortic root (as opposed to simple replacement of the valve) in all cases. The allograft was replaced with another aortic allograft (11), a pulmonary autograft (9), or a mechanical valved-conduit (5). There were 2 operative deaths (8%). There were 2 late deaths (non-valve related) and 2 repeat valve failures (requiring a third root replacement) in the aortic allograft group. 2 of the 9 pulmonary autografts failed early. There were no late deaths or valve failures in the pulmonary autograft or mechanical valve groups at a mean follow-up of  5.5 years.

 

¨         This report is unique in reporting an experience with repeat aortic root replacement in children who have undergone previous aortic root replacement with an aortic allograft. It nicely details the magnitude and technical challenge of this undertaking. In midterm follow-up, a pulmonary autograft or mechanical valve appeared to provide better outcome than a repeat aortic allograft.


Scheule AM, Zurakowski D, Blume ED, Stamm C, del Nido PJ, Mayer JE, Jonas RA. Arterial switch with a single coronary artery. J Thorac Cardiovasc Surg 2002;123:1164-72.

 

From 1983-2000, 53 patients with a single coronary artery underwent an arterial switch operation. These patients comprised 6% of the total undergoing arterial switch. 35 patients had a single right, and 18 a single left coronary. Early mortality was 5/53 (9%), with the last death in 1991. Survival at 5 and 10 years was 87%. Survival was lower for patients with a single right coronary with the left main coronary passing behind the pulmonary artery. Reintervention was most commonly for right ventricular outflow tract obstruction. Freedom from reintervention was 82% at 10 years, and was lower for patients with a single left coronary with right coronary passing anterior to the aorta.

 

¨         A single coronary artery can present technical challenges during an arterial switch procedure, and has been previously identified as a risk factor for operative mortality. This report details an extensive experience with single coronary arterial switches. It shows that in the current era, operative risk has become very low. The expanded version of this article provides an excellent discussion of the history, anatomy and surgical approach in patients with transposition and a single coronary (Scheule AM, Jonas RA. Management of transposition of the great arteries with single coronary artery. Pediatric Cardiac Surgery Annual of the Seminars in Thoracic and Cardiovascular Surgery 2001;4:34-57).    

 

 

 

Shaddy RE, Curtin EL, Sower B, Tani LY, Burr J, LaSalle B, Boucek MM, Mahony L, Hsu DT, Pahl E, Burch GH, Schlencker-Herceg R, for The Pediatric Randomized Carvedilol Trial in Children with Heart Failure Study.  The pediatric randomized carvedilol trial in children with chronic heart failure: Rationale and design.  Am Heart J 2002; 144:383-389.

 

The  authors describe the rationale and design of an ambitious study of carvedilol, a medication with both alpha-receptor and beta-receptor blocking properties.  Although carvedilol has been approved for the treatment of heart failure in adults, little is known about its safety, efficacy, pharmacokinetics and dosing profile in children.  This study will enroll 150 children between birth and 17 years of age with chronic symptomatic heart failure caused by systemic ventricular systolic dysfunction.  The primary objective is to evaluate the efficacy of carvedilol given twice daily for eight months vs. placebo.  The authors will study a composite measure of clinical outcomes (as well as the individual components), including hospitalizations for heart failure, mortality, symptoms of heart failure, as well as assessing the effects of carvedilol on echo indices of ventricular function and remodeling.  In addition, the pharmacokinetics and daily dosing information for carvedilol in pediatric patients with heart failure will be examined.

 

·                    This study will help define important information for treatment of heart failure in children.  Although carvedilol has become a mainstay of therapy for adults with congestive heart failure, there are virtually no data available regarding its use in children. This well-designed study should help answer some important questions, and pediatric cardiologists caring for patients with heart failure should consider contacting one of the participating centers listed in this article.   
Sharma S, Maron BJ, Whyte G, Firoozi S, Elliott PM, McKenna WJ. Physiologic limits of left ventricular hypertrophy in elite junior athletes: Relevance to differential diagnosis of athlete’s heart and hypertrophic cardiomyopathy.  J Am Coll Cardiol 2002; 40:1431-1436. 

 

To explore the possible use of serum hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) levels as predictive indicators for occurrence of coronary artery lesions ( CAL ) in Kawasaki disease (KD), levels were measured in 41 patients with KD and in 25 afebrile controls.  Serum HGF levels were higher in patients with KD than in controls (p<0.05).  Univariate analysis showed correlations between CAL and the following variables: duration of fever (p=0.018), serum C-reactive protein concentration (p=0.024), albumin concentration (p=0.009), serum VEGF level (p=0.009), and serum HGF level (p=0.055).  Multivariate analysis showed that serum HGF and VEGF levels and presence of edema were major risk factors for the occurrence of CAL .  The authors describe a new risk classification system using HGF level, VEGF level, and presence of edema, which showed a sensitivity of 100% and a specificity of 94.4% for identifying CAL .

 

·                    HGF and VEGF levels are not routine laboratory assays in most hospitals, and thus at the present time have limited use for clinicians managing patients with Kawasaki disease.  Nonetheless, I found this a fascinating study for several reasons.  First, because HGF and VEGF levels are elevated during the acute phase of KD, if this information could be obtained, it could help guide diagnosis, prognosis, and therapy of patients with KD at the time of the acute illness.  In addition, levels of HGF and VEGF could potentially be useful for monitoring various treatment modalities for KD, both for the individual patient as well as for a series of patients with KD,  possibly guiding therapy to reduce the incidence or severity of CAL .  Although this study did not address the issue, it would be interesting to know if elevated HGF and VEGF are present in other disease states, or are specific to KD.  If so, it would give added impetus for hospitals and laboratories to include measurement of these levels.


Du Z-D, Koenig P, Cao Q-L, Waight D, Heitschmidt M, Hijazi ZM.  Comparison of transcatheter closure of secundum atrial septal defect using the amplatzer septal occluder associated with deficient versus sufficient rims.  Am J Cardiol 2002; 90:865-869.

 

The authors measured ambulatory and clinic blood pressure (BP) in 18 adults with coarctation of the aorta (14 corrected) and 36 controls, and measured the coarctation diameter using transesophageal echocardiography.  Systolic clinic and ambulatory BP levels were higher in patients than controls (clinic 146 vs. 119 mm, ambulatory 140 vs. 124 mm).  The relationship between BP and coarctation diameter was stronger for ambulatory daytime BP than clinic BP.  In surgically corrected patients, only the correlation between ambulatory systolic BP to coarctation diameter was statistically significant.

 

·                    There appears to be a strong correlation between ambulatory systolic BP and the diameter of uncorrected or corrected coarctation diameter.  The authors demonstrate that ambulatory systolic BP correlates more closely with coarctation diameter, suggesting that ambulatory BP measurements may provide important clinical information in addition to standard clinic BP measurements.


 Yi MS, Kimball TR, Tsevat J, Mrus JM, Kotagal UR .  Evaluation of heart murmurs in children: Cost-effectiveness and practical implications.  J Pediatr 2002; 141:504-511.

 

To determine the risk of sudden death in patients with right atrial isomerism (asplenia) after palliation, 154 patients were identified.  The 1-year and 5-year survival was 72% and 50%, with 22 sudden deaths (defined as acute cardiovascular collapse from which death occurred within 24 hours), which included 14% of all patients studied.  Sudden death tended to occur in infancy or early childhood (mean 12 months, median 9 months).  Mechanisms were sudden tachyarrhythmia in 2, sudden cardiac but nontachyarrhythmic (sudden, severe cyanosis) in 15, and sudden noncardiac in 5 (fulminant sepsis with positive blood culture).  The incidence of sudden death decreased with age until 3 years of age.

 

·                    Because of the high morbidity and mortality in patients with asplenia, as well as the rarity of this lesion, I found this large study enlightening and clinically useful.  When counseling parents of children with asplenia, having specific information regarding the high chance of mortality (as well as morbidity) is important to include in the discussion. Knowledge of the mechanisms is interesting, and could help guide therapy for infants and young children with asplenia.


Clark JA, Lieh-Lai MW, Sarnaik A, Mattoo TK.  Descrepancies between direct and indirect blood pressure measurements using various recommendations for arm cuff selection.  Pediatrics 2002; 110:920-923.

 

The goal of this study was to evaluate the diagnostic value of gadolinium-enhanced three-dimensional (3D) magnetic resonance angiography (MRA) in patients with congenital and acquired anomalies of the pulmonary and systemic veins.  61 patients were evaluated, including 37 with pulmonary venous anomalies, 17 with systemic venous anomalies, and 7 with pulmonary and systemic venous anomalies.  Compared with available diagnostic information by other modalities, all known or suspected venous anomalies were imaged by 3D MRA.  Following 3D MRA diagnoses, 10 interventional and 15 operations were performed.  In 74% of patients, 3D MRA either diagnosed previously unsuspected venous anomalies (28%) or added new clinically important information (46%).  The mechanism of pulmonary vein compression in 8 patients was determined by MRA but not by other imaging modalities.  Using a grading system for MRA image quality (1=nondiagnostic to 5=excellent), the average grade was 4.6 0.6.

 

·                    Although MRI has been shown in the past to be helpful for evaluation of pulmonary and systemic venous malformations, one limitation has been that traditional MRI techniques require relatively long scan times.  Because gadolinium-enhanced 3D MRA provides a much faster technique (studies typically require less than one minute for image acquisition), and the diagnostic information appears superior to traditional modalities such as echo or cardiac catheterization, it appears from this study that this technique should be the method of choice for evaluation of patients with suspected pulmonary or systemic venous anomalies in centers in which it is available.  I would suggest taking a look at the original paper for some lovely images.

 

 

 

 

May/June 2003 issue [24.3]

Humpl T, Campbell R, Stephens D, Van Arsdell G, Benson LN, Holtby HM, Slutsky AS, Adatia I. Levels of exhaled nitric oxide before and after surgical and transcatheter device closure of atrial septal defects in children. J Thorac Cardiovasc Surg 2002;124:806-10.

 

30 children undergoing closure of atrial septal defects underwent measurement of nitric oxide in end-tidal expiratory gas before and after closure. Fifteen children had surgical closure utilizing cardiopulmonary bypass, and 15 had device closure in the catheterization laboratory. There was no significant difference between the 2 groups in age, weight, or ASD size. After surgical closure, exhaled nitric oxide levels decreased by 21%, while after device closure, levels increased by 23%. 

 

¨         Previous work by this group has demonstrated that exhaled nitric oxide levels decrease after surgical closure of left-to-right intracardiac shunts. This decrease may reflect either endothelial cell injury caused by cardiopulmonary bypass, or decreased pulmonary blood flow due to the closure of the shunt. The current study indicates that the decrease in pulmonary blood flow following ASD closure is not primarily responsible for decreased nitric oxide production.  Instead, decreased exhaled nitric oxide levels may be a marker of  pulmonary vascular injury, with decreased endogenous nitric oxide production, in children undergoing surgical closure of left-to-right intracardiac shunts.


Tweddell JS, Hoffman GM, Mussatto KA, Fedderly RT, Berger S, Jaquiss RDB, Ghanayem NS, Frisbee SJ, Litwin SB. Improved survival of patients undergoing palliation of hypoplastic left heart syndrome: lessons learned from 115 consecutive patients. Circulation 2002;106(suppl I):I-82-I-89.

 

A consecutive series of 115 infants underwent stage1 palliation ( Norwood procedure) from 1992-2001. 77% of the patients had hypoplastic left heart syndrome.  Compared to patients operated from 1992 to 1996, patients operated in the current era (1996-2001), had improvements in hospital survival (93% vs. 53%), survival to stage 2 palliation (81% vs. 44%), and actuarial survival to 5 years (72% vs. 41%). By multivariate analysis, continuous superior vena cava oximetry was associated with improved hospital survival. Larger size of the ascending aorta, and perioperative use of phenoxybenzamine were associated with improved survival to stage 2 palliation. In the current era, shorter duration of circulatory arrest was associated with improved survival to stage 2 palliation. 

 

¨         This report documents the outstanding results currently achieved for stage 1 palliation of hypoplastic left heart syndrome and its variants at the Children’s Hospital of Wisconsin . Over the period of the study, several new perioperative strategies were introduced, including continuous monitoring of mixed venous oxygen saturation, modified ultrafiltration, parenteral phenoxybenzamine, aprotinin, and low-flow cerebral perfusion with limited circulatory arrest. Other factors not included in the analysis, but likely contributing to the results, were changes in personnel, such as surgeons and intensivists. The paper clearly details the components of an innovative approach which yields excellent results.


Cohen MI, Bush DM, Gaynor JW, Vetter VL, Tanel RE, Rhodes LA. Pediatric pacemaker infections: twenty years of experience. J Thorac Cardiovasc Surg 2002;124:821-7.

 

A retrospective review was performed of all pacemakers implanted in children between 1982 and 2001. Infections were classified as superficial cellulitis, or deep pacemaker pocket infection. A total of 385 pacemakers (224 epicardial and 161 endocardial) were implanted in 267 patients at a mean age of 8.4 years. There were 19 (4.9%) superficial infections, and 9 (2.3%) deep pocket infections. Eight of the 9 deep infections occurred following pacemaker revisions. All superficial infections were successfully treated with intravenous antibiotics alone. Two patients who underwent partial lead extraction for deep infection had recurrent infection necessitating a further operation to remove the remaining lead. In multivariate analyses, trisomy 21 and pacemaker revision were predictors of infection.  

 

¨         This extensive experience with pacemaker implantations in children provides important information on a rare problem. It suggests that patients with trisomy 21, and repeat pacemaker operations should be approached with particular attention to antisepsis. Superficial infection is well treated with antibiotics. However, patients with deep pocket infection generally require complete removal of hardware for successful treatment.


Maher KO, VanDerElzen K, Bove EL, Mosca RS, Chenoweth CE, Kulik TJ. A retrospective review of three antibiotic prophylaxis regimens for pediatric cardiac patients. Ann Thorac Surg 2002;74:1195-200.

 

Three antibiotic prophylaxis protocols were serially used for pediatric cardiac surgical patients between 1993 and 1998. In all three protocols, cefazolin was administered before operation. The cefazolin was then: (Protocol 1, 786 patients) continued as long as chest tubes or central venous catheters were in place; (Protocol 2, 1095 patients) continued for 48 hours only; (Protocol 3, 2039 patients) continued as long as chest tubes were in place, but not for central venous catheters. Surgical site infection rates for the 3 protocols were: 2.0%, 6.6%, and 1.7%; the rate for protocol 2 was significantly higher than for protocols 1 and 3. Bloodstream infections per 1000 days for the 3 protocols were 2.2, 6.5, and 5.0; the rate for protocol 1 was significantly lower than for protocols 2 and 3.

¨         This experience suggests that antibiotic prophylaxis until removal of chest tubes may decrease the rate of surgical site infection in pediatric cardiac surgical patients. It leaves open questions of whether a prospective, randomized study would give a similar result, and whether the severity (morbidity and mortality) of the infections was affected by the antibiotic protocol.

 

 

Kannankeril PJ, Pahl E, Wax DF. Usefulness of troponon I as a marker of myocardial injury after pediatric cardiac catheterization.  Am J Cardiol 2002; 90:1128-1132.

 

To investigate the degree of myocardial injury with pediatric cardiac catheterization, cardiac troponin I (cTnI) levels were measured following 73 catheterizations.  Patients having interventionial procedures expected to cause myocardial injury (Group II) had higher cTnI levels than patients  undergoing diagnostic procedures and interventions not expected to cause myocardial injury (Group I) (median 2.65 vs. 0.3 ng/ml, p<0.001).  Most pediatric interventional catheterization procedures are associated with myocardial injury, as evidenced by elevation of cTnI. Radiofrequency ablation causing higher levels than other interventions (median 3.7 vs. 1.75, p<0.05), while most diagnostic procedures had no detectable myocardial injury. 

 

·                    Cardiac troponin I is a useful, proven marker for evaluating coronary artery disease and myocardial injury in adults.  Experience and reports in pediatric patients, however, are much more limited.  This straightforward study provides useful information which demonstrates which procedures are most likely to produce myocardial damage in pediatric patients undergoing cardiac catheterization.  As more is learned about this important tool, its exact diagnostic and therapeutic role will likely also emerge.  This report is a nice addition to the literature with regards to the use of troponin I in the care of pediatric cardiac patients.  


de Jongh S, Lilien MR, Stroes ESG, Bakker HD, Kastelein JJP.  Early statin therapy restores endothelial function in children with familial hypercholesterolemia.  J Am Coll Cardiol 2002; 40:2117-2121.

 

To determine whether simvastatin improves endothelial function in children with familial hypercholesterolemia (FH), 50 children with FH (9 to 18 years) were randomized to receive simvastatin or placebo for 28 weeks.  19 healthy controls were also studied.  Endothelial function, measured by flow-mediated dilation of the brachial artery (FMD), which is used as a surrogate marker of cardiovascular disease (CVD) in adults, was measured in all at baseline and after 28 weeks.  Baseline FMD was impaired in children with FH vs/ controls (p<0.024).  In patients with FH receiving simvastatin, FMD improved significantly, while FMD did not change in those receiving placebo (absolute increase 3.9% vs. 1.2%, p<0.05).  In the simvastatin FH group, FMD increased to a level similar to the non-FH controls (15.6% vs. 15.5%), while total cholesterol and LDL-cholesterol decreased significantly.  There were no significant differences with regard to lab value abnormalities (ALT, AST, CK) between simvastatin and placebo FH groups, and no adverse events were reported.

 

·                    Although hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) have been shown to reverse endothelial dysfunction in adult patients with hypercholesterolemia, statins have not previously been studied in a series of children with hypercholesterolemia.  I found intriguing the authors’ concluding statement that “the current data vigorously support the institution of statin therapy at early stages, when endothelial dysfunction is still amenable to complete normalization.”  Although this important study appears to show short-term benefits and safety of statin use in children with FH (over a 28 week period), I feel that cautious optimism is perhaps a better summary of my own thoughts regarding the implications of this interesting report.  I agree with the editorial comment accompanying this article that “demonstration projects to determine the safety of hypolipidemic drugs in this patient population, and in particular the use of statins, are urgently needed before the wide-scale adoption of this aggressive approach can be advocated.”  I look forward to future longer-term studies which will more completely address safety issues in children with hyperlipidemia.


Brignole M, Croci F, Menozzi C, Solano A, Donateo P, Oddone D, Puggioni E, Lolli G.  Isometric arm counter-pressure maneuvers to abort impending vasovagal syncope.  J Am Coll Cardiol 2002; 40:2053-2059.

 

The authors hypothesized that isometric arm exercises could increase blood pressure (BP) during the phase of impending vasovagal syncope and allow the patient to avoid losing consciousness.  19 patients with tilt-induced vasovagal syncope had a single-blind, placebo-controlled, randomized, cross-over tilt-table efficacy study and a clinical follow-up feasibility study.  During the tilt, when patients had symptoms of impending syncope, handgrip (HG) treatment, administered for 2 minutes caused an increase in systolic BP (SBP) from 92 to 105 mm Hg, 63 % became asymptomatic, and 5 % developed syncope.  In contrast, when patients had placebo treatment after symptoms of impending syncope developed, SBP decreased from 91 to 73 mm Hg (p = 0.008), 11 % (p = 0.02) became asymptomatic, and 47 % developed syncope (p = 0.01).  Patients were trained to self-administer arm testing treatment as soon as symptoms of syncope occurred.  During 9 months of follow-up, treatment was performed in 95/97 episoedes of impending syncope (98%) and was successful in 94/95 (99 %).

 

 

·                    Although this study of  tilt-positive vasovagal syncope was performed on adults, its content and conclusions are likely important for clinicians caring for children with vasovagal syncope as well, since the underlying population studied did not have underlying coronary artery disease (similar to patients of pediatric cardiologists).  Since most pediatric cardiologists evaluate many patients with this symptom (especially teenagers), it would be interesting to evaluate use of this technique in pediatric patients as well.


Kamphuis M, Vogels T, Ottenkamp J, van der Wall EE, Verloove-Vanhorick SP, Vliegen HW.  Employment in adults with congenital heart disease.   Arch Pediatr Adolesc Med 2002: 156:1143-1148.

 

The objective of this study was to evaluate job participation, job problems and career-related problems in adults with complex congenital heart disease (CHD compared with adults with mild CHD and reference groups.  76 patients with complex CHD and 80 with mild CHD (age 17-32 years) completed a self-reported questionnaire on employment and problems (response rat 70%).  Findings were compared to reference data.  59% (45/76) of patients with complex CHD had a paid job; 76% (61/80) with mild CHD had a paid job.  Patients older than 25 years with complex  CHD had lower job participation (64%) than the general population (83%).  Type of CHD and level of education were significantly and independently related to job participation (odds ratio 4.8 and 4.7 respectively).  55% (42/76) of those with severe CHD experienced disease-related career problems vs. 1% (1/80) with mild CHD.

 

·                    Because knowledge of the natural history of a particular disease is paramount in determining prognosis and interventions, and because the “unnatural history” (what happens when we intervene) is equally important in patients undergoing various forms of therapy, I found this study enlightening and clinically useful.  When counseling parents of children with congenital heart disease, or in caring for such patients, it is useful to be aware of not only the length of life, but also of other important aspects, such as job participation and quality of life issues.


Barker PCA, Ensing G, Ludomirsky A, Bradley DJ, Lloyd TR, Rocchini AP.  Comparison of simultaneous invasive and noninvasive measurements of pressure gradients in congenital aortic valve stenosis.  J Am Soc Echocardiogr 2002; 15:1496-1502.

 

The goal of this study was to compare different noninvasive measurements with simultaneous catheter gradients to identify which best predicts the catheter peak to peak gradient.  25 simultaneous Doppler and catheter measurements of aortic stenosis gradient were obtained in 14 children prior to valvuloplasty; 11 of these were also evaluated after valvuloplasty.  The Doppler peak instantaneous pressure gradient overestimated the catheter peak to peak gradient but correlated well with the catheter peak instantaneous gradient.  The Doppler mean systolic gradient correlated well with the catheter peak to peak gradient at low gradients and underestimated higher catheter gradients, but agreed well at all levels with the catheter mean gradient.  The modification of a catheter-derived correlation equation showed good correlation with the catheter peak to peak gradient (slope 1.14; intercept –1.8; R 0.92).  The authors conclude that the catheter peak to peak gradient can be accurately estimated noninvasively using estimated pressure recovery or correlation equations incorporating Doppler measurements.

 

·                    Because much of the classic literature and “gold standards” in pediatric cardiology were created in the pre-echo era, one of the challenges for the modern pediatric cardiologist is to interpret non-invasive measurements such as Doppler findings, and make decisions regarding catheterizations and surgical interventions.  This fine study provides useful intervention for the clinician caring for patients with aortic stenosis, and should help guide evaluation and therapy for such patients.

 

 

September/October 2003 issue [24.5]

Pizarro C, Norwood WI . Pulmonary artery banding before the Norwood procedure. Ann Thorac Surg 2003;75:1008-10.

 

Two newborns with hypoplastic left heart syndrome presented with severe imbalance of Qp:Qs, low systemic perfusion, and multiorgan dysfunction. Their initial base excesses were -20 to -30. Standard pharmacologic and ventilatory strategies were unsuccessful in restoring adequate systemic perfusion. Each underwent operative banding of the bilateral branch pulmonary arteries, with resulting hemodynamic stabilization. A successful Norwood procedure was then carried out 6 and 10 days later.

 

¨         This article describes a valuable management option for the neonate with hypoplastic left heart syndrome and severe pulmonary overcirculation, too critically ill to undergo a primary Norwood procedure. In these 2 patients, the mechanical limitation to pulmonary blood flow provided by the bands effectively allowed recovery of end organ dysfunction. This approach could be combined with ductal stenting for longer-term palliation, or as here, with a subsequent neonatal Norwood procedure.


Devaney EJ, Charpie JR, Ohye RG, Bove EL. Combined arterial switch and Senning operation for congenitally corrected transposition of the great arteries: patient selection and intermediate results. J Thorac Cardiovasc Surg 2003;125:500-7.

 

Over a 10-year period, 23 patients with corrected transposition and no pulmonary stenosis were entered into a protocol aimed at anatomic repair (double switch operation), placing the morphologic left ventricle and mitral valve in the systemic circulation. Eleven additional patients were not entered into this protocol, either because they were too clinically well (4), or beyond an optimal age for left ventricular retraining (7). Among the 23 patients, 15 were candidates for a double switch due to right ventricular dysfunction or tricuspid insufficiency, and 8 due to associated uncorrected defects. Fifteen of the 23 patients underwent preliminary pulmonary artery banding. Seventeen patients underwent a double switch operation, 9 with, and 8 without a preliminary band. There were no early or late deaths over a mean follow-up of 36 months. Among the patients undergoing a preliminary band, the oldest to have a successful double switch was 4 years old. 1 patient aged 7 years underwent heart transplantation following  a preliminary band and double switch.; 2 patients aged 12 and 14 years had failure of banding.

 

¨         This article documents excellent intermediate-term results of a double switch procedure for selected patients with corrected transposition and a normal pulmonary valve.  It also agrees with other studies which indicate that the potential for left ventricular reconditioning by pulmonary artery banding is limited in older patients.


De Oliveira NC, David TE, Ivanov J, Armstrong S, Eriksson MJ, Rakowski H, Webb G. Results of surgery for aortic root aneurysm in patients with Marfan syndrome. J Thorac Cardiovasc Surg 2003;125:789-96.

 

From 1979 to 2001, 105 patients with Marfan syndrome, aged 12-75 years (mean 35 years), underwent surgery for aortic root aneurysm. Forty-four underwent aortic root replacement; 61 underwent aortic valve-sparing operations. Two types of valve-sparing operations were used: reimplantation (replacement of the entire aortic root down to the annulus, 39 patients) and remodeling (replacement of the sinuses of Valsalva, 22 patients). In the aortic valve-sparing group, there were no operative deaths; survival at 10 years was 96%. At 10 years freedom from reoperation was 100%, and freedom from aortic insufficiency greater than 2+ was 75%. Over a mean follow-up of 49 months, the diameter of the aortic annulus and sinuses tended to increase after remodeling, but not reimplantation.

 

¨         Preserving the aortic valve during operation for aortic root aneurysm in patients with Marfan syndrome has become increasingly used since the pioneering efforts of Dr David, and Sir Magdi Yacoub. This article updates Dr. David’s extensive experience. It supports this group’s current recommendations to undertake elective repair at an aortic root diameter of 4.5-5 cm; in patients with normal aortic valve cusps, the valve is preserved, rather than replaced. The particular valve-sparing technique of reimplantation has a lower incidence of perioperative bleeding, and more effective stabilization of the aortic annulus, and is favored by this group.


Azakie A, Russell JL, McCrindle BW, Van Arsdell GS, Benson LN, Coles JG, Williams WG. Anatomic repair of anomalous left coronary artery from the pulmonary artery by aortic reimplantation: early survival, patterns of ventricular recovery and late outcome. Ann Thorac Surg 2003;75:1535-41.

 

From 1952 to 2000, 47 patients with anomalous left coronary artery from the pulmonary artery were repaired by aortic reimplantation. Concomitant mitral valve repair was used in 1 patient. Hospital survival was 92%. Five required postoperative ECMO support. Significant preoperative predictors of postoperative ECMO support were presentation in critical condition, ventricular arrhythmias, lower ejection fraction, and more severe left ventricular dilation. Over a mean follow-up of 4.7 years, there were no late deaths. Four patients underwent late reoperation for coronary ostial stenosis (in 3), supravalvar pulmonary stenosis (in 1), and severe mitral regurgitation (in 1). Freedom from reoperation at 10 years was 93%. The prevalence of moderate-plus mitral insufficiency improved from 38% preoperatively to 9% at follow-up. Echocardiography demonstrated that ejection fraction and left ventricular dilation tended to normalize by 4 months, and mitral insufficency to improve by 8 months after repair.

 

¨         This 48-year experience demonstrates the excellent early and late outcomes achievable for patients with anomalous left coronary artery.  The need for postoperative mechanical support is primarily dependent on preoperative condition, and it is frequently successful when used. This report also adds information on the time course of ventricular function recovery, and reinforces the concept that mitral insufficency frequently improves without direct intervention on the valve.

 

 

Koppel RI ,  Druschel CM,  Carter T, Goldberg BE, Mehta PN, Tawler R, Bierman FZ.  Effectiveness of pulse oximetry screening for congenital heart disease in asymptomatic newborns. Pediatrics 2003; 111:451-455.

 

The goal of this study was to determine the usefulness of pulse oximetry in screening asymptomatic newborns for critical congenital cardiovascular malformation (CCVM), 1,1281 asymptomatic newborns had pulse oximetry at 24 hours of life and cardiac ultrasound was performed on infants with saturation < 95% . Of these newborns, 3 cases of CCVM were detected. (total anomalous pulmonary venous return x 2, truncus arteriosus). Two infants with negative screens were readmitted (coarctation, hypoplastic left pulmonary artery with aorto-pulmonary collaterals); there was one false-positive screen. Six infants with CCVM were symptomatic before screening. 9 live infants with CCVM were born from a group of 15 fetuses with CCVM detected by fetal echocardiography. The prevalence of critical CCVM among all live births was one in 564 and among the screened population was 1 in 2256 (Sensitivity 60% specificity 99.95%, positive predictive value 75%, negative predictive value 99.98%, accuracy 99.97%).

 

·                    Since congenital heart disease continues to carry significant morbidity and mortality, early detection is important for optimal care of infants with critical lesions. Pulse oximetry, which is widely available, non-invasive, and inexpensive, has proven its usefulness in --------children with possible congenital heart disease for decades. As the authors suggest, a case can also be made for routine screening of all infants with this tool.

 

Schwimmer JB, Burwinkle TM, Varni JW.  Health-related quality of life of severely obese children and adolescents .  JAMA. 2003; 289:1813-1819

 

With a goal of examining the health-related quality of life (QOL) of obese children and adolescents , 106 such subjects (ages 5-18 years) were evaluated. Child self-report and parent proxy report was used with a pediatric QOL inventory generic core scale (range 0-100). Compared with healthy children and adolescents, obese children and adolescents reported lower health-related QOL (mean total score 67 vs 83 for healthy children and adolescents). Obese children and adolescents were more likely to have impaired health-related QOL than healthy subjects (odds ratio 5.5), and were similar to children and adolescents with cancer (odds ratio 1.3). Based on the parent proxy report , the BMI z score was inversely correlated with the total score (r= -0.246, p =<0.01), social functioning (r = -0.347,p<  0.001), and psychosocial functioning (r = - 0.209, p = 0.03).

 

·                    As increasing numbers of children are becoming obese (the authors note that currently 1 out of 7 US children and adolescents are obese) it is important for physicians to be aware of QOL issues for these individuals. Besides the obvious long-term risk of obesity, it appears that more immediate concerns are present for these children and adolescents, further highlighting the importance of addressing this epidemic.

 


Ades A, Sable C, Cummings S, Cross R, Markle B, Martin G.  Echocardiographic evaluation of umbilical venous catheter placement.  Journal of Perinatology (2003) 23,24-28 doi:10.1038/sj.jp.7210851.

 

This study was designed to compare techniques for guiding and confirming placement of umbilical venous catheters (UVCs) using two-dimensional echocardiography. 53 newborns with UVCs were studied. UVC position was assessed by AP and lateral chest x-ray and oxygenation data. The accuracy was then compared to echocardiography with contrast injection. UVCs were located ideally at the right atrial/inferior vena cava junction in only 12 (23%) of 53 patients , and 24 (45%) were incorrectly placed in the left atrium. The authors conclude that echocardiography should be considered to confirm correct placement of UVCs.

 

*          Although   I   have   seen   many   examples  of  misplaced  UVCs,  most

institutions  apparently  do  not  routinely  confirm  catheter  position  of 

the  UVC  with echocardioghraphy.   In  order  to  avoid  this  problem, 

following  the  authors’ recommendations  for  echocardiography  to 

check  placement  of  UVC  would  seem  a  reasonable  and  straight-

forward  solution.


Al-Attar I, Orav JE, Exil V, Vlach SA, Lipshultz SE, Predictors of cardiac morbidity and related mortality in children with acquired immunodeficiency syndrome . J A Coll Cardial 2003;41:1598-605.

 

The goal of this study was to determine the prevalence of cardiovascular dysfunction and its predictors in children with acquired immunodeficiency syndrome (AIDS). The authors reviewed the medical records, echos, ecgs, and holter monitor studies of 68 children with AIDS. The median time from AIDS diagnosis to death or end of follow-up was 1.0 year. 19 (28%) had serious cardiac events after AIDS diagnosis. Of 43 patients who died, 15 (35%) had cardiac dysfunction. Mulitvariate analyses showed that recurrent bacterial infections, wasting, encephalopathy, male gender, and an earlier year of AIDS diagnosis were predictors of serious cardiac events. Increased risk for cardiac death was found in patients with male gender, a low age-adjusted CD4 count, and a low age-adjusted IgG level.

 

·                    Even  though  advanced,  serious  cases  AIDS/HIV  have  become  less common  in  developed  countries  in  recent  years,  HIV  remains  a    serious  threat  in  many  developing  nations.  This  study  nicely   highlights  the  risk  of  cardiac  events in  patients  with  AIDS,  and  may  help  direct  attention  to those  patients  who  are  most  at  risk  for suffering  cardiac  events.


Elliot, DA, Kirk EP, Yeoh T, Chandar S, McKenzie F, Taylor P, Grossfield  P, Fatkin D, Jones O, Hayes P, Fenely M, Harvey RP. Cardiac homebox gene NKX2-5 mutations and congenital heart disease. Associations with atrial septal defect and hypoplastic left heart syndrome.  

 

The authors studied a cohort of 146 individuals with secundum atrial septal defect (ASD), pantent foramen ovale (PFO) with paradoxical embolism, or hypoplastic left heart syndrome (HLHS). Patients were examined for mutations in the cardiac transcription gene NKX2-5. among 103 ASD M, was found in members of a family with ASD without AV conduction block and one NKX2-5 mutation positive child from this family had HLHS. No mutations were subsequently found in 18 patients with sporadic or familial HLHS. The authors conclude that though NKX2-5 mutations are a relatively infrequent cause of sporadic ASD and HLHS, screening for such mutations may be warranted in individuals with ASD and a positive family history

 

·                    Despite  the  fact  that  most  patients  with  congenital  heart  disease apparently  do  not  have  an  obvious  genetic  component,  certain families  and  individuals  may  benefit  from  genetic  testing.  This  study provides  useful  information  for  physicians  caring  for  these  patients.

 

 

 

 

2004 Issues:


January/February 2004 issue [25.1]

Outcome of Children with End-Stage Congenital Heart Disease Waiting for Cardiac Transplantation. Mital S, Addonizoio LJ, Lamour JM, and Hsu DT (2003) J Heart Lung Transplant 22:147-153.

 

Summary:  Forty-six patients, with a mean age of 8.3 + 8 years, were listed for transplantation for a diagnosis of congenital heart disease.  The patients were divided into those who died while awaiting (Group I) and those who survived to transplantation (Group II).  The two groups were then compared to evaluate the pre-transplant outcome and risk factors for children awaiting heart transplantation for congenital heart disease.  Primary indications for transplantation were ventricular dysfunction in 36 (78%), failed Fontan in 8 (18%), and severe hypoxemia in 2 (4%).  Seventy percent of the patients (32) were status 1.  Of the 41 patients that remained listed for transplantation (5 patients were de-listed), 12 (29%) died waiting.  The primary cause of death was severe heart failure in 10.  Mean time to death on the waiting list was 29 + 28 days and time to transplant was 94 + 176 days.  The results revealed that mean age of listing was younger in Group I (2.6 + 4 years) compared with Group II (9.1 + 7 years p<0.05).  Mean duration of heart failure was shorter in Group I (3.6 + 3.9 months) compared with Group II (25 + 33 months, p<0.05).  Children had a superior 50-day actuarial survival on the waiting list (91%) compared to infants (38%, p<0.05). 

 

Editor’s (RO) Comments: Congenital heart disease is the indication for heart transplantation in 70% of infants and 50% of children ages 1-10 years however, there are few data available to describe their pre-transplant course.  In summary, 71% of patients with congenital heart disease listed for transplantation survived to transplant, which is consistent with previous reports.  Significant findings were that younger age and more rapid onset of heart failure were significant risk factors for pre-transplant death.  Risk factors previously reported in another series, which did not reach significance in the current study, include prolonged waiting time and a diagnosis of hypoplastic left heart syndrome.  The primary limitation of this study is that it is a relatively small and heterogenous sample size.  These data are useful in counseling families of children awaiting heart transplantation.  In addition, the finding that age <1 year at listing was an independent risk factor, combined with the fact that most of these patients had early and rapid onset of heart failure, suggests that difficulty in early recognition and assessment of heart failure in infants with congenital heart disease may negatively impact a timely referral for transplantation evaluation.  Thus, the development of heart failure in the infant with congenital heart disease should prompt early intervention and subsequent early consideration for transplantation in those patients failing medical treatment. 

 

 

Late Follow-Up of 1095 Patients Undergoing Operation for Complex Congenital Heart Disease Utilizing Pulmonary Ventricle to Pulmonary Artery Conduits. Dearani JA, Danielson GK, Puga FJ, Schaff HV, Warnes CW, Driscoll DJ, Schleck CD, and Ilstrup DM. (2003) Ann Thorac Surg 75:399-411.

 

Summary:  1095 patients undergoing placement of a pulmonary ventricle to pulmonary artery conduit before July 1992 were evaluated for outcome.  Mean age at conduit placement was 9.6 + 8.2 years.  A porcine-valved Dacron conduit was used in 730, homograft in 239 and non-valved conduit in 126.  The results revealed that early mortality decreased from 23.5% prior to 1980 to 3.7% for the most recent decade.  Actuarial survival for hospital survivors at 10 and 20 years was 77% + 1.5% and 59.5% + 2.6%, at a mean follow-up of 10.9 years.  Multi-variant analysis revealed independent risk factors for late mortality to be male gender, older age at operation, diagnosis of TGA, corrected TGA, truncus or univentricular heart, and pulmonary ventricle to systemic ventricle pressure ration > 0.72 (all p < 0.03).  Freedom from conduit related reoperation at 10 and 20 years was 55.5% + 2% and 31.9% + 2.7%.  Multi-variant analysis revealed homograft conduit, diagnosis of TGA, younger age at operation and smaller conduit size to be significant independent risk factors for reoperation (all p < 0.007).  At last follow-up, 84% of survivors were in NYHA classification I or II. 

 

Editor’s (RO) comments: Dearani and associated are to be congratulated on the remarkable magnitude of this undertaking of over 1000 patient undergoing pulmonary ventricle to pulmonary artery conduit placement.  While there are study limitations inherent to such a large group, including population heterogeneity, and evolution of medical care, surgical technique and conduit technology, there are several interesting aspects to this series.  The first is that porcine valved Dacron conduits demonstrated superior durability when compared to homografts, which is in contradistinction to other published reports.  The reasons for this conflict are likely multifactorial.  The difference is at least partially explained by the relatively advanced mean age (9.6 + 8.2 years) and large mean conduit size (approximately 20 mm) compared to other studies.  In addition, cryopreserved pulmonary homografts, which are generally accepted as the preferred type of homograft, made up only 2% of the conduits placed.  The remaining homografts were either irradiated or cryopreserved aortic homografts, which are generally seen as inferior to pulmonary homografts.  The current approach of the authors is, in fact, to use cryopreserved pulmonary homograft for infants, due to the superior surgical handling characteristics.  After the first 2-3 years of life, the authors prefer to use porcine valved conduits for reconstruction.  Also significant, was the finding that the majority of late deaths were cardiac related.  The authors suggest that many of these deaths may have been conduit related.  We would strongly agree with the authors that consideration should be given to conduit replacement even in the asymptomatic patient when pulmonary ventricular pressure approaches systemic pressure.  In addition, conduit replacement should be undertaken in the presence of significant arrhythmia, progressive ventricular dysfunction, tricuspid regurgitation or decreasing functional status.  Lastly, the finding that younger age of operation was associated with improved late survival, suggests that early complete repair in infancy may be preferable over initiation palliation. 

 

Use of bovine jugular vein to reconstruct the right ventricular outflow tract: Early results.  Boudjemline Y, Bonnet D, Massih T, Agnoletti G, Iserin F, Jaubert F, Sidi D, Vouhe P.  (2003) J Thorac Cardiovas Surg 126;490-7.

 

Summary: The early results of bovine jugular vein conduits in the pulmonary outflow tract in 31 patients were evaluated.  Median age at implantation was 3.4 years (range 0 to 21 years).  Median conduit diameter was 14 mm (range 12 to 20 mm).  The patients were evaluated by echocardiography at the time of discharge and 3 months after surgery.  Patients with significant pulmonary regurgitation and/or stenosis subsequently underwent cardiac catheterization.  Four patients died during follow-up, with 1 death being due to conduit thrombosis.  At 3 months, pulmonary regurgitation was absent or trivial in 19, mild in 2, and severe in 3 of the 24 survivors.  Four patients also had non-fatal conduit-related morbidity.  One patient had transient thrombus formation treated with anticoagulation.  The remaining 3 patients required reoperation for conduit failure at a mean follow-up of 4.3 months.  Indication for conduit replacement was aneurysmal dilatation of the conduit proximal to severe stenosis at the distal anastomosis due to neointimal proliferation. 

 

Editor's (RO) comments: The ideal conduit for the pediatric patient, demonstrating freedom from the development of stenosis, durability of valve competency and ultimately growth, remains elusive.  One of the more recently available conduits is a valved bovine jugular vein derivative.  The excellent valvar competence at 3 months (80% absent or trivial) is balanced by other relatively disappointing morbidity, mortality and durability.  The authors currently employ a policy of anti-platelet therapy for 6-12 months following implantation, in an attempt to improve these outcomes.  The study limitations are primarily due to the very small sample size.  Interestingly, the initial experience with the bovine jugular vein conduit at our institution and others has been more favorable (data unpublished).  It would be interesting to know further details about the patients' distal pulmonary arteries and the adequacy of the surgical repair, perhaps with pulmonary ventricle to systemic ventricle pressure ratios.  Further long term studies would be needed to determine the role for bovine jugular vein conduits in the reconstruction of the right ventricular outflow tract. 

 

Interim Mortality in Infants with Systemic-to-Pulmonary Artery Shunts.  Fenton KN, Siewrs RD , Rebovich B, Pigula FA.  (2003)  Ann Thorac Surg 76:152-7

 

Summary:  146 infants, who underwent placement of systemic-to-pulmonary artery shunts and survived hospitalization, were evaluated for outcome.  All patients were age 60 days or less.  The underlying diagnosis was single ventricle lesion in 90 cases.  Of these discharged patients, 21 (14%) died after discharge and before further planned surgery.  Seventeen (81%) were clinically doing well, while 4 were being treated for cardiorespiratory issues prior to death.  Of the asymptomatic patients, 4 had recently (within 72 hours) been seen in the emergency room or pediatrician’s office for nonspecific complaints and an additional 3 patients died within 24 hours of a minor procedure (hernia repair, cardiac catheterization, and esophagoscopy).  Mortality was unrelated to aspirin administration, shunt size, presence of another source of pulmonary blood flow, or single ventricle anatomy.  Autopsies were available in 15 (71%) of the patients.  Death was related to shunt thrombosis in 5 (33%), lung pathology in 3 and myocardial infarction in 2.  Five autopsies were nondiagnostic.  The authors concluded that the optimal management strategy for these patients includes the avoidance of shunts when possible, proceeding to further palliation as soon feasible and careful evaluation and monitoring during times of physiologic stress (e.g. minor procedures, dehydration due to fever, poor feeding or vomiting). 

 

Editor's (RO) comments:  As hospital survivals have improved for single ventricle and other complex congenital heart lesions requiring initial palliative shunting, interim mortality has become an important concern.  The finding of a mortality rate of 14% is consistent with other studies.  The inherent instability of shunt dependent physiology is underscored by these data and confirms the importance of aggressive follow up.  Indeed, the Children's Hospital of Wisconsin recently published their results with active surveillance of shunted patients following discharge, which was successful in decreasing interim mortality.  While the authors did not find that aspirin therapy provided the beneficial effect on interim mortality or the incidence of shunt thrombosis, other authors have documented a protective effect. 

 

Evidence-Based Referral Results in Significantly Reduced Mortality After Congenital Heart Surgery.  Allen SW, Gauvreau K, Bloom BT, and Jenkins KJ.  (2003) Pediatrics 112:24-28.

 

Summary: A retrospective, cohort comparison over a 10-year period for small Midwestern pediatric cardiology practice was undertaken to review the mortality rates of their patients following congenital heart surgery.  Data were divided into 3 time periods, August 1992-July 1995 (period 1), August 1995-July 1998 (period 2), and August 1998-July 2002 (period 3).  During period 3, a change in referral policy dictated that all surgical cases would be selectively referred to surgical centers that were determined to have low mortality rates for specific cardiac lesions.  Hospital discharge data from 5 states were used to provide comparison.  Risk adjustment was performed using the Risk Adjustment in Congenital Heart Surgery-1 method.  Of the 514 congenital surgical cases, 507 (98.6%) were available for analysis.  Unadjusted mortality rates were 9.3% in period 1, 5.9% in period 2, and 1.3% in period 3.  Unadjusted mortality rates for the benchmark data were 6.4% in 1992, 4.8% in 1996, and 3.7% in 1998.  After risk adjustments, the surgical results for the center remained similar to the benchmark data for periods 1 and 2.  However, following the change in referral policy, there was a significant reduction in mortality in period 3, with a four-fold decrease in the odds of death (odds ratio =0.24, p=0.02). 

 

Editor's (RO) comments: The volume/outcome relationship has been demonstrated for several conditions, including congenital heart disease.  Other studies have documented the improvements in outcome when patients requiring congenital heart surgery are transferred to so-called "Centers of Excellence" for their surgical procedures.  Recent collaborations in data collection and benchmarking by the European Association for Cardio-thoracic Surgery, the Society for Thoracic Surgery, the Association for European Paediatric Cardiology and the Aristotle Risk Adjustment System underscores the importance of this topic.  Furthermore, the increasing availability of outcomes data to patients via such outlets as the internet, and increasing pressures from Medicaid and other 3rd party payers for successful outcomes will continue to fuel the debate on evidence-based referral strategies.

 

Right ventricle-pulmonary artery shunts in first-stage palliation of hypoplastic left heart syndrome.  Sano S, Ishino K, Kawada M, Arai S, Kasahara S, Asai T, Masuda Z, Takeuchi M, Ohtsuki S.  (2003) J Thorac and Cardiovas Surg 126:504-10.

 

Summary:  19 consecutive infants with a median age of 9 days (range 6-57days) and median weight 3.0 kg (range 1.6 to 3.9 kg) underwent a modified Norwood operation with a right ventricle to pulmonary artery (RV-PA) shunt.  Of these 19 patients, there were 17 survivors (89%), including 3 patients weighing less than 2 kg.  The two hospital deaths were due to sudden cardiac arrest and septicemia.  There were additional 2 late deaths from hypoxemia related to shunt obstruction.  13 patients have undergone bidirectional Glenn (BDG), 2 patients are awaiting BDG, 7 are awaiting Fontan and 4 have undergone Fontan.  Overall survival for this group is 62%.  These results are compared to historical data from the same institution for a Norwood operation with modified Blalock-Taussig (BT) shunt, which revealed a hospital survival of 53%.  The authors underscore the marked decrease in complexity of ICU care for the patients receiving the RV-PA shunt. 

 

Editor's (RO) comments: At our institution, it is has been our bias to continue to use the standard Blalock-Taussig shunt and reserve the RV-PA conduit for specific indications.  Our overall survival for a standard risk Norwood operation with the modified BT shunt has been in access of 90%.  However, high risk patients, such as very low birth weight infants, continue to have significant hospital mortalities approaching 50%.  As such, we do agree that the RV-PA shunt maybe particularly beneficial in low birth weight infants where controlling pulmonary blood flow is problematic.  We agree with the authors that the effects of the right ventriculotomy on the systemic right ventricle with respect to long term function and arrhythmia generation remains to be seen.  We also agree that another concern is related to the additional volume overload related to flow reversal in the non-valved conduit.  Similar to the authors conclusion, our group and others have also found that the RV-PA shunt tends to become stenotic over time and may result a decrease in pulmonary artery growth compared to patients receiving a standard BT shunt.  One potential benefit of the RV-PA shunt would be a decrease interim mortality.  While such a decreased inter-stage mortality was not demonstrated in this study, it has been reported by other authors.  One final role for the RV-PA shunt may be in the patient with the diminutive ascending aorta (< 1.5-2.0mm) to optimize coronary perfusion. 

 

Early Experience with a Modified Norwood Procedure Using Right Ventricle to Pulmonary Artery Conduit. Mahle WT, Cuadrado AR, Tam KT.  (2003)  Ann Thoac Surg 76:1084-9.

 

Summary:  11 patients undergoing a Norwood operation with RV-PA conduit were retrospectively evaluated and compared to 22 historical controls undergoing a conventional Norwood procedure with a BT shunt.  Median age at operation was 5 days (range 1-31 days).  There was no significant difference in the incidence of aortic atresia, aortic diameter, birth weight, ventricular function or degree of tricuspid insufficiency between the two groups.  Hospital survivals were identical at 81%.  No significant differences were detected in postoperative morbidity, including duration of mechanical ventilation, ICU stay, and hospital stay.   Patients who underwent conventional Norwood procedures had significantly lower diastolic blood pressures in the early postoperative period, when compared to patients with the RV-PA conduit (38.4 + 4.4 mmHg versus 49.5 + 4.3 mmHg, p=0.001).  One-year survival rates were also similar at 81% for the RV-PA conduit and 73% for the modified BT shunt.  Two patients developed a pseudoaneurysm at the proximal anastomosis of the RV-PA conduit.  While not statistically significant, 4 deaths occurred after hospital discharge, all in the conventional Norwood cohort.  Evaluation prior to the Glenn procedure revealed no difference in ventricular function, tricuspid insufficiency, RVEDP Qp:Qs ratio or mean PA pressure. 

 

Editor's (RO) comments:  This retrospective, historically controlled study from an institution with very good survival rates for the standard Norwood procedure found no improvement in survival with the RV-PA conduit.  They also did not detect any significant increase in morbidity related to either technique.  Pulmonary artery growth, which has been suggested as a concern with the RV-PV conduit, was not reported.  However, adequate growth may be inferred from the Qp:Qs ratios and mean pulmonary artery pressures, which were equivalent between the two groups.  While not universally reported, the higher diastolic blood pressure in the RV-PA conduit group may result in superior coronary perfusion.  This superior coronary perfusion may in turn have a positive impact on interim mortality, and cardiac and other end-organ function. 

 

Right Ventricle to Pulmonary Artery Conduit Improves Outcome After Stage I Norwood for Hypoplastic Left Heart Syndrome.  Pizarro C, Malec E, Maher KO, Januszewska K, Gidding SS, Murdison KA, Bafa JM, Norwood WI .  (2003) Circulation 108[suppl II] :II-155-160.

 

Summary:  A retrospective review of 56 consecutive patients undergoing a Norwood procedure for hypoplastic left heart syndrome with either an RV-PA conduit (n=36) or a modified Blalock-Taussig shunt (n=20).  The median age of the patients was 4.5 days (range 1 to 40 days) and median weight was 3.1 kg (range 1.8 to 4.1 kg).  There were no significant differences between the RV-PV conduit and modified BT shunt groups with respect to demographics, anatomy, or valvar and ventricular function.  The operative survival for the RV-PA conduit group was higher than the BT shunt group (92% vs 70%, p=0.05).  Patients in the RV-PA conduit group had fewer ventilatory manipulations for management of Qp:Qs (1/36 vs 8/20, p=0.001), delayed sternal closure (6/36 vs 7/20, p=0.001) and need for ECMO (5/36 vs 7/20, p=0.036).  Patients in the RV-PA conduit group had higher diastolic blood pressures at 1, 8, 24 and 48 hours after the Norwood procedure (all p=0.001).  There is no difference in interm mortality between the two groups (p=0.184).  All six month survivors underwent a successful hemi-Fontan procedure in both groups.

 

Editor's (RO) comments: This 3rd article on the RV-PA conduit has both similarities and differences from the previous articles.  The authors showed a significant improvement in survival with the RV-PA conduit.  This finding, which is in agreement with the article by Sano and colleagues, but in contradistinction to the article by Molly et al, may be explained primarily by the lower initial survivals with the modified BT shunt in those articles that did note a significant survival benefit.  These 3 selected articles are part of a much larger group of manuscripts and abstracts reflecting the growing popularity of the RV-PA conduit.  Debate remains regarding the short and long-term risks and benefits of the RV-PA conduit versus the modified Blalock-Taussig shunt.  The role for the RV-PA modification, particularly at centers with excellent results utilizing the modified BT shunt, remains to be determined pending further clinical trials. 

 

 

 


Hemodynamic profile after the Norwood procedure with right ventricle to pulmonary artery conduit. Maher KO, Pizarro C, Gidding SS, Januszewska K, Malec E, Norwood WI , Murphy JD. Circulation 2993:108:782-784.

 

Summary:  The authors hypothesized that a right ventricle to pulmonary artery conduit (instead of a systemic to pulmonary artery shunt) would result in hemodynamic changes consistent with a more stable balance of systemic, pulmonary and coronary perfusion in patients with hypoplastic left heart syndrome (HLHS) who undergo the Norwood operation.  Hemodynamic data were obtained during cardiac catheterization before the hemi-Fontan procedure from 24 patients with HLHS.  The first 10 had a systemic to pulmonary artery shunt, and the next 14 had a right ventricle to pulmonary artery conduit in the initial operation.  The conduit group had a higher aortic diastolic pressure (55 vs. 42 mm Hg), a narrowed systemic pulse pressure (43 vs. 64 mm Hg), a lower Qp:Qs (0.92 vs. 1.42), a higher coronary perfusion pressure (46 vs. 32 mm Hg), and a higher ratio of pulmonary artery diameter to descending aorta diameter (1.51 vs. 1.37).  The authors conclude that in HLHS after the Norwood operation, the right ventricle to pulmonary artery conduit modification produces hemodynamic changes consistent with improved coronary perfusion and a more favorable distribution of systemic, pulmonary and coronary blood flow.

           

 

Editor's (DGT) comments: This new modification of the Norwood operation for HLHS is quite intriguing.  Given the significant morbidity and mortality in such patients due to inadequate coronary perfusion, inappropriate amounts of pulmonary blood flow, and other issues, a ventricular to pulmonary artery conduit seems to make theoretical sense, and this study indicates it also results in favorable hemodynamics.  The only concern I had with the paper is the omission of any mortality information in these patients (how many survived from birth to stage I to cardiac catheterization?), which was surprising since the authors discuss the theoretical advantages of the newer modification in improving survival.  Still, this is a very interesting study, and I look forward to learning more about this modification in the future.

 

 

Quality of life after repair of transposition of the great arteries.  Culbert EL, Ashburn DA, Cullen-Dean G, Joseph JA, Williams WG, Blackstone EH, McCrindle BW, and the Congenital Heart Surgeons Society. Circulation 2003; 108:857-862.

 

Summary:  In this interesting study,  the authors sought to assess quality of life of children with transposition of the great arteries TGA who were previously enrolled in a prospective study during the transition in management strategy from atrial to arterial switch operation (1985-1989).  Child Health Questionnaires were completed by 306 of 708 survivors at a mean age of 13 years.  Diagnosis included TGA (n=202, 66%), TGA/ventricular septal defect (VSD) (n=84, 27%), and TGA/VSD/pulmonary stenosis (n=20, 7%).  Repair type was arterial switch (n=189, 62%), atrial switch (n=84, 34%; Senning=58, Mustard=47), or Rastelli (n=12, 4%).  Children with TGA scored significantly higher than published norms in all categories except self-esteem.  TGA/VSD/pulmonary stenosis was associated with lower scores than TGA and TGA/VSD in physical functioning (p=0.002), general health perceptions (p=0.012), and mental health (p=0.048).  Arterial repair was associated with higher scores than atrial or Rastelli repair in physical functioning (p<0.001), pain (p=0.004), mental health (p=0.019), self-esteem (p=0.004), and general health perceptions (p<0.001).  The authors conclude that quality of life and health status as perceived by children 11 to 15 years after TGA repair is excellent when compared with published normative data and is better after arterial switch operation than after atrial repair.

 

 

Editor's (DGT) comments: I found this series enlightening for several reasons.  First, it is interesting that all groups with TGA perceive an excellent quality of life.  In light of the modern use of the arterial switch for these patients, it is encouraging that patients who had switches appear to be doing better than those receiving the atrial switch.  Because the field of pediatric cardiology is constantly changing, the evidence proving the relative efficacy of one therapy over another may take a number of years to produce; in this case, it looks like the right decision was made.


Syncope in children and adolescents and the congenital long QT syndrome.Khositseth A, Martinez MW, Driscoll DJ, Ackerman M.    Am J Cardiol 2003; 92:746-749.

 

 

Summary:  From a population-based epidemiologic cohort of 151 children and adolescents who sought medical attention for syncope, screening 12-lead electrocardiograms were obtained from 118 patients (79 female) to determine the frequency of significant QT prolongation.  The distribution of heart rate corrected QT intervals (QTc) was compared with age- and sex-matched controls.  While 38% of fainters and 31% of controls had a QTc between  420 and 470 ms, only one patient had QTc>470 ms.  The authors conclude that the electrocardiogram is unable to conclusively exclude long QTc syndrome as a possible etiology of the syncopal event in most cases.

 

Editor's (DGT) comments: In this study of children and adolescents with a history of syncope, the long QT syndrome was quite rare.  This information should be useful for clinicians caring for children and teenagers with syncope.  Although the yield of  the electrocardiogram is quite low for these patients, I don’t think most pediatric cardiologists are quite ready to eliminate this test from the diagnostic regimen.

 


Accuracy of analog telephonic stethoscopy for pediatric telecardiology.Belmont JM, Mattioli LF.    Pediatrics 2003; 112:780-786.

 

Summary:  The authors tested a narrow-band-width telephonic stethoscope (TS) for pediatric telecardiology.  76 consecutive patients (mean age 10 years) in a pediatric cardiology outpatient clinic were studied.  A pediatric cardiologist examined the patients with his acoustic stethoscope (AS), and a second examined them a few minutes later using a remote TS; the TS was placed by nurse as directed by the remote examiner via intercom.  TS/AS agreement was satisfactory for presence/absence of heart disease (K=0.63) and for organic, functional, vibratory, diastolic aortic, and diastolic pulmonic murmurs (K range: 0.65-0.75).  For other murmurs and all heart sounds, TS/AS agreement was either unsatisfactory (K<0.60) or indeterminate because prevalence was 0.

 

Editor's (DGT) comments: In recent years there has been a dramatic increase in telemedicine, including wide-band-width transmission of digital echocardiograms and digital electronic cardiostethoscopy in older children.  Because the technology described in this study uses very-narrow-bandwidth, which uses ordinary telephone service, TS may have wider applications than digital electronic cardiostethoscopy, since special lines are not needed..

 


Bowles NE, Ni J, Kearney DL, Pauschinger M, Schultheiss HP, McCarthy R, Detection of viruses in myocardial tissues by polymerase chain reaction: Evidence of adenovirus as a common cause of myocarditis in children and adults.  Hare J, Bricker JT, Bowles KR, Towbin JA. J Am Coll Cardiol, 2003; 42:466-472..

 

Summary:  The purpose of this study was to analyze cardiac tissue and blood for viral genomes using polymerase chain reaction (PCR) to define the common viral etiologies of myocarditis by age group.  Cardiac samples were obtained for PCR analysi from patients with myocarditis (n=624) and dilated cardiomyopathy (DCM) (n-149).  The study consisted of 116 neonates, 191 infants, 87 toddlers, 110 children, 92 adolescents and 177 adults.  After nucleic acids were extracted from sample tissue, PCR and reverse transcription PCR were performed to detect the genomic sequences of multiple viruses.  Viral genome was amplified from 239 (38%) of the 624 samples from myocarditis patients, including 142 adenovirus, 85 enterovirus, 18 CMV, 6 parvovirus, 5 influenza A, 5 HSV, 3 EBV, 1 RSV, and 26 with dual infection.  Although virus was detected in 30 of 149 DCM patient samples (20%), only adenovirus (n-18) and enterovirus (n=12) were detected. Of  the 215 controls (165 age-matched children and 50 adults undergoing open heart transplant or autopsy), just three (1.4%) amplified virus: enterovirus from one and CMV from two. The authors conclude that PCR identified adenovirus as the most common virus in the myocardium of children and adults with myocarditis and DCM.

 

Editor's (DGT) comments: Although enteroviruses, particularly Coxsackievirus B, has been considered the most common cause of acute myocarditis, diagnosis has been based on identification of virus by peripheral culture methods and/or serial serology.  This excellent, multicenter trial, using a powerful technology only available in the past few years, provides strong evidence that adenoviruses are an important cause of myocarditis in children and adults As the authors suggest in their discussion, new therapies could possibly be developed to treat or prevent myocarditis.  Antiviral agents or vaccinations may prove useful in the future, which might decrease the severity or ultimately eliminate this challenging disease.

 

 

 

March/April 2004 issue [25.2]

The Registry of the International Society for Heart and Lung Transplantation:  Sixth Official Pediatric Report – 2003

 

Boucek MM, Edwards LB, Keck BM, Trulock EP, Taylor DO, Mohacsi PJ, Hertz MI (2003) J Heart-lung Transplant 22:636-652

 

This is the sixth official report on pediatric thoracic organ transplantation from the Internal Society for Heart and Lung Transplantation.  This year’s analysis shows little change in the number of heart transplants or in the break down of the ages of the recipients, with the most common age for heart transplant remaining 0-1 years.  Of these infants, approximately 75% were transplanted for congenital heart disease.  This indication decreased throughout the 1990’s and has plateaued since about 1999.  Overall survival for heart transplant for the most recent era, 1999-2001, was significantly improved over the previous eras.  Currently, the one-year survival is approximately 85%.  Statistically significant differences in survival between age groups remain, with infants having a greater early mortality.  However, by 12-years posttransplant, both childhood and adolescent survival curves have intersected with the infant survival curves, indicating a lower rate of late mortality in the infant group.  Encouragingly, the half-life for the infant age group is not even computable, because by 17 years of follow-up, it has not penetrated the 50% survival barrier.  The overall number of pediatric lung transplants has decreased slightly since the late 1990’s, with approximately 60 procedures being done in 2001.  Compared to previous eras, there is no significant difference in actuarial survival for the most recent era of 1998-2001.  The half-life in the most recent era is 3.1 years and 10-year overall survival is less than 40%.  The volume of pediatric heart-lung transplantation continues to decrease through the period of analysis.  Overall, the number of these procedures performed worldwide in 2001 was approximately 10.  The calculated half-life for heart-lung transplantation for the 1-10 year old age range is 2.0 years and for 11-17 year old range it is 3.3 years.  By 10 years after transplantation, the overall survival is approximately 20%.

 

Editorial comments:

 

While the number of pediatric heart transplants has remained stable and there had been decreases in lung and heart-lung transplantation, the overall number of heart, lung and heart-lung recipients have remained consistent over the past year.  This reflects the overall improvement in survival in recent years, particularly in heart transplantation.  While there is an initial higher mortality, infant recipients of a heart or lung transplantation have continued to show a trend towards increased conditional survival, when compared to older age groups.  This article also reviews the risk factors for mortality following transplantation.  The most interesting is a direct correlation between creatinine and survival for heart transplantation.  There are also interesting trends reported in the use of both induction therapy and maintenance immunosuppression.

 

 

 

Home surveillance program prevents interstage mortality after the Norwood procedure

 

Ghanayem NS, Hoffman GM, Mussatto KA, Cava JR, Frommelt PC, Rudd NA, Stelzer MM, Bevandic SM, Frisbee SJ, Jaquiss RDB, Litwin SB, Tweddell JS (2003) J Thorac Cardiovasc Surg 126:1367-1377

 

24 patients undergoing a Norwood procedure for hypoplastic left heart syndrome (HLHS) or a variant of HLHS at the Children’s Hospital of Wisconsin were discharged with a home surveillance program.  These patients were compared to 63 similar patients who were discharged prior to the initiation of the home surveillance program.  The program consisted of discharging the patients with an infant scale and pulse oximeter.  The parents were instructed to contact the physician in the event of an arterial oxygen saturation less than 70%, an acute weight loss of more than 30 grams in 24 hours, or failure to gain at least 20 grams during a three day period.  The results showed an interstage mortality among infants surviving to discharge of 15.8% (9/57) in the control group and 0% (0/24) in the group receiving home surveillance (P=0.039).  Surveillance criteria were breached for 13 of the 24 patients in the surveillance group.  Twelve for decreased oxygen saturation and 1 with poor weight gain alone.  These 13 patients underwent bidirectional Glenn anastomoses at an earlier age (3.7 + 1.1 months), when compared patients not breaching surveillance criteria (5.2 + 2.0 months, P=0.028).  A analysis of the growth curves showed reduced growth velocity between 4 and 5 months of age, with a plateau in growth beyond 5 months of age.

 

Editorial Comments:

 

As survivals for the Norwood operation for HLHS and it’s variants has improved to greater than 90% at selected centers, the continued interstage attrition has become a major area of interest.  The reported interstage mortality rates from these centers continue to be from 10-15%.  While this study has the admitted limitations of small sample size and lack of randomization, the absence of mortality in the study group is of interest.  As noted by the authors, reduced growth velocity between 4 and 5 months of age and the plateau in growth beyond 5 months of age, may suggest that the value of delaying stage 2 palliation beyond that time may be unwarranted.

 

 

 

 

Stenting the Neonatal Arterial Duct in Duct-Dependent Pulmonary Circulation:  New Techniques, Better Results

 

Gewillig M, Boshoff DE, Dens J, Mertens L, Benson LN (2004) J Am Coll Cardiol 43:107-112

 

10 neonates and infants with duct-dependent pulmonary circulation underwent stent placement in their patent ductus arteriosus.  Only patients with a short and straight duct were considered for the study.  Patients with a so called “reverse oriented ductus” were excluded.  Early in the experience, the procedure was only offered to patients with a high surgical risk.  As the experience grew, the procedure was offered to all patients fulfilling criteria for stent placement.  The median age was 6 days (range, 1-42 days) and median weight was 3.3 kg (range, 2.5-3.7 kg).  Seven of the 10 patients had either pulmonary atresia or pulmonary stenosis.  These patients underwent balloon dilatation of the pulmonary valve, with or without radiofrequency perforation of membranous atresia, and placement of a stent.  Two patients underwent stent placement for excluded single branch pulmonary arteries and 1 patient underwent duct stenting for complex single ventricular physiology.  The current techniques described different from previous reports in that the stent length was chosen slightly longer than the duct length with minimal protrusion into the aorta and some protrusion into the pulmonary artery.  All patients were successfully stented with either 1 or 2 stents.  There was one mortality from sepsis 4 days after stenting.  The remaining 9 patients underwent either interval complete repair, or, in the case of pulmonary stenosis with RV hypoplasia, adequate RV growth to allow spontaneous stent occlusion.

 

Editorial Comments:

 

The stenting of the ductus arteriosus to maintain patency in patients who have limited pulmonary blood flow is gaining in popularity.  Selected centers are combining duct stenting with either surgical or intraluminal branch pulmonary artery banding as the initial stage of palliation for hypoplastic left heart syndrome.  I am somewhat concerned that the authors do not address the issue of relatively unrestrictive pulmonary blood flow, particularly in patients expected to undergo single stage palliation, ultimately with a Fontan procedure.  Despite the fact that our institution remains inclined to proceed with complete repair in the neonatal period or with surgical shunting, we have found that in selected cases this technique for duct stenting has been very useful.  Recent examples of duct stenting combined with bilateral branch pulmonary artery banding include a 30-week, 1.2 kg premature neonate with hypoplastic left heart syndrome and a newly presenting 6-week old with HLHS and severe RV dysfunction.  Overall, the use of expandable stents to maintain ductal pertinency is a useful adjunct in caring for the patent with ductal dependent congenital heart disease.

 

 

 

Patterns of Recurrence of Congenital Heart Disease

 

Gill HK, Splitt M, Sharland GK, Simpson JM (2003) J Am Coll Cardiol 42:923-929

 

A total of 14,116 fetal echocardiograms were performed over a 10-year period from 1990-1999 at tertiary fetal cardiology unit.  Of these referrals, 6,640 were for pregnancies where a first-degree relative was known to have congenital heart disease (CHD).  The index case was the mother in 1,119 cases (17%), the father and 370 (6%), and a sibling in 5,151 (77%).  In this cohort, CHD was diagnosed in 178 (2.7%) of the 6,640 pregnancies.  For the study, concordance was defined as CHD identical to the index case and group concordance defined as a lesion belonging to a similar group of CHD (i.e. left heart defects, septal defects).  Overall exact concordance was 37% and overall group concordance was 47%, however it should be noted that the range for exact concordance was very wide (0-80%).  A high concordance was seen in isolated atrial ventricular septal defect, with a rate of 80%, and for laterality defects (64%).  It is also important to note that while ventricular septal defect had an exact concordance rate of 55%, there was a very wide range of defects and of severity.

 

Editorial Comments:

 

This study’s primary limitation is that it is not population based, and therefore the incidences do not reflect true concurrent risks.  However, these data are still useful.  As health care professionals caring for patients and their families with congenital heart disease, we are frequently asked what the risk of having another child with CHD is.  Overall, the recurrence rate of 2.7% in this high-risk population is of useful when counseling our patients with congenital heart disease as they approach childbearing years, or for the parents of our patients considering having additional pregnancies.

 

 

 

Neurodevelopmental status at eight years in children with dextro-transposition of the great arteries:  The Boston Circulatory Arrest Trial

 

Bellinger DC, Wypij D, duPlessis AJ, Rappaport LA, Jonas RA, Wernovsky G, Newburger JW (2003) J Thorac Cardiovasc Surg 126:1385-1396

 

This manuscript reviews the 8 year follow-up of the well-known Boston Circulatory Arrest Trial.  In this single center trial, infants with D-transposition of the great arteries underwent arterial switch operation after random assignment to either deep hypothermic circulatory arrest or hypothermic low flow cardiopulmonary bypass.  Of the initial 171 patients, 165 remain alive at 8 years.  Of these patients 155 underwent evaluation.  The treatment groups did not differ in most measured outcomes, including neurologic status, IQ, academic achievement, memory, problem solving, and visual-motor integration.  Children assigned to circulatory arrest performed worse on several test of motor function.  Those children were assigned to low flow cardiopulmonary bypass were found to have a more impulsive response style on a continuous performance test of vigilance and worse behavior as rated by teachers.  Mean scores of the cohort as a whole on standardized tests of global function (e.g. IQ) were well within the normal range, and only slightly lower than expected.  However, specific testing revealed some aspects of neurodevelopmental status in the cohort as a whole was below the expected.  These categories included academic achievement, fine motor function, visual-spacial skills, working memory, hypothesis generating, sustained attention, and higher-order language skills.  The authors concluded that circulatory arrest is generally associated with greater function deficit then low flow cardiopulmonary bypass.  Although patients have continued to perform adequately, neonatal bypass techniques can be associated with increase risk for poor neurodevelopmental outcome.

 

Editorial Comments:

 

The landmark Boston Circulatory Arrest Trial continues to generate interesting data on outcomes of children undergoing repair for D-transposition of the great arteries.  One significant study limitation in using this study to compare the two techniques lies in the fact that in the low flow bypass group, patients with transposition of the great arteries and intact ventricular septum underwent a mean of 14 minutes + 12 minutes of circulatory arrest and those with transposition and ventricular septal defect underwent 31 + 16 minutes of circulatory arrest.  However, the use of circulatory arrest and hyperthermic low flow cardiopulmonary bypass continues to be an important method for the treatment of neonates with complex congenital heart disease.  While newer techniques such as regional cerebral perfusion are being employed, there are no data to support improved outcomes.  Thus, the outcomes of these children who have undergone either circulatory arrest or low flow cardiopulmonary bypass continue to be of great interest to the health professional caring for patients with congenital heart disease.

 

 

 

The effect of duration of deep hypothermic circulatory arrest in infant heart surgery on late neurodevelopment:  The Boston Circulatory Arrest Trial

 

Wypij D, Newburger JW, Rappaport LA, duPlessis AJ, Jonas RA, Wernovsky G, Lin M, Bellinger DC (2003) J Thorac Cardiovasc Surg 126:1397-1403

 

This report is an analysis of the patients from the Boston Circulatory Arrest Trial.  The developmental neurologic and speech outcomes at 8 years for the cohort were analyzed in an effort to determine the association between the duration of circulatory arrest and the risk of neurodevelopment dysfunction.  Comparing the patients assigned to circulatory arrest or low flow bypass, no difference was found in terms of full scale or performance IQ.  Using circulatory arrest as a continuous variable, longer circulatory arrest was significantly associated with a lower full scale IQ (p=0.04) and performance IQ (p=0.02).  Academic achievement did not differ significantly between treatment groups, or when duration of circulatory arrest was used as a continuous variable.  Children assigned to circulatory arrest tended to take longer to complete the grooved pegboard test for fine motor function (p=0.06).  Longer duration of circulatory arrest was associated with a longer time to complete the test (p=0.01).  The Mayo Test for Apraxia of Speech and Oral Apraxia was used to evaluate speech production.  Children assigned to circulatory arrest, as well as duration of circulatory arrest was found to be significant (p=0.002, p< 0.001, respectively).  The 6 outcome variables, which were either significant or tended towards departure of linearity, were used in an attempt to explore the potential threshold effect of circulatory arrest duration.  The cut points remained quite consistent between the variables, ranging between 35 and 43 minutes.  A multi-variant analysis revealed no heterogeneity.  Therefore a common cut-point was calculated at 41 minutes, with a 1-sided 95% lower confidence limit of 32 minutes.  This study suggest that utilizing this institution’s techniques of bypass and circulatory arrest, children who’s circulatory arrest duration exceeds 41 minutes were at higher risk for poor neurodevelopmental outcome.  It also suggests that it may not be necessary to take special measures to avoid circulatory arrest for short periods of times.

 

Editorial Comments:

 

The “safe duration for circulatory arrest” has been suggested to be anywhere from 39-65 minutes.  This manuscript represents the first experimental data available to estimate a threshold after which the duration of circulatory arrest may lead to an adverse neurodevelopmental outcome.  As mentioned in the previous editorial comments on the companion manuscript, the comparison between achieving groups is somewhat difficult to interpret as for example, those patients assigned to low flow bypass with d-TGA/VSD had an average of 31 + 16 minutes of circulatory arrest.  However, the data evaluating circulatory arrest is a continuous variable are quite interesting.  While the authors appropriately note that the 41 minute threshold cannot be reviewed as a “universally safe” duration for circulatory arrest due to the multiple other variables influencing neurodevelopmental outcome, the authors continue to produce very valuable information from the landmark Boston Circulatory Arrest Trial.

 

 

 

Long-term functional results of the one and one half ventricular repair for the spectrum of patients with pulmonary atresia/stenosis with intact ventricular septum

 

Numata S, Uemura H, Yagihara T, Kagisaki K, Takahashi M, Ohuchi H (2003) Eur J Cardio-thoraci Surg 24:516-520

 

This retrospect review with historical controls reports one center’s experience with the one and one half ventricular repair.  Seven patients with pulmonary atresia with intact ventricular septum and 6 patients with pulmonic stenosis and hypoplastic RV underwent a one and one half ventricular repair.  Length of follow-up was 10 + 4 years (range, 3-15 years).  All patients survived to hospital discharge.  One patient died 9 years postoperatively of an arrhythmia.  Treated from arrhythmia was 80% at 10 years and 20% at 12 years.  Two patients have subsequently undergone conversion to Fontan circulation and none to biventricular repairs.  Cardiac catheterization performed at 1, 5, and 10 years postoperatively demonstrated no change in right ventricular end diastolic volume or tricuspid valve diameter.  Cardiac index remained stable at 2.4 + 0.6 l/min per m2 at 5 and 10 years.  Right atrial pressures were 9 + 3mmHg and 12 + 2mmHg at 5 and 10 years, respectively.  Exercising testing showed an anaerobic threshold of 16.6 + 3.4ml/kg per minute and 13.1 + 2.7ml/kg per minute at 5 and 10 years, respectively.  These values were found to be equivalent to patients undergoing a Fontan procedure for tricuspid atresia or pulmonary atresia with intact ventricular septum and inferior to those patients undergoing a biventricular repair for pulmonary atresia with intact ventricular septum.

 

Editorial Comments:

 

The role of the one and a half ventricle repair continues to be controversial.  The literature would suggest that the procedure can be performed with a low mortality, however longer term benefits are unknown.  Proponents of the procedure suggest that the maintenance of the right ventricle in the pulmonary circuit will allow for increased cardiac output across the lungs during exercise.  In addition, these authors suggest that it may allow for growth of the right ventricle and tricuspid valve for later conversion to biventricular repair.  However, in this study the authors found no increase in right ventricular end diastolic volume or tricuspid valve diameter over the follow-up period.  Not surprisingly, exercise testing revealed inferior anaerobic thresholds when compared to patients with pulmonary atresia with intact ventricular septum undergoing biventricular repair.  However, the patients with a one and a half ventricle repair also had equivalent exercise performance and rates of arrhythmia to patients with similar diagnoses undergoing a Fontan procedure, which brings into questions it’s role in the management of  these patients.

 

 

 

The influence of hemodilution on outcome after hypothermic cardiopulmonary bypass:  Results of a randomized trial in infants

 

Jonas RA, Wypij D, Roth SJ, Bellinger DC, Visconti KJ, du Plessis AJ, Goodkin H, Laussen PC, Farrell DM, Bartlett J, McGrath E, Rappaport LJ, Bacha EA, Forbess JM, del Nido PJ, Mayer JE, Newburger JW (2003) J Thorac Cardiovasc Surg 126:1765-1774

 

This manuscript reports a single center, randomized, evaluator-blinded study of 2 hemodilution protocols during hypothermic cardiopulmonary bypass in infants.  The primary end points were lowest cardiac index in the first 24 hours postoperatively and the Psychomotor Development Index and Mental Developmental Index of the Bayley Scales at 1 year of age.  There were 147 patients, of which 74 were assigned to the lower-hematocrit strategy (goal 20%) and 73 to the high-hematocrit strategy (goal 30%).  In the intent-to-treat analysis, lower nadirs of cardiac index, higher lactate levels 60 minutes after cardiopulmonary bypass, and a greater percentage increase in total body water on postoperative day #1 was seen in the lower-hematocrit group.  Blood product use and adverse events were similar in the 2 groups.  At 1 year of age, 113 patients underwent Bayley testing.  The lower-hematocrit group had lower scores on the Psychomotor Development Index, and similar Mental Development Index scores.  Results using hematocrit as a continuous variable were similar to those based upon the intent-to-treat analyses.

 

Editorial Comments:

 

While there are several studies with conflicting results in adults undergoing cardiac surgery with varying levels of hematocrit, the results in the pediatric population are distinctly lacking.  This study would suggest that hematocrit levels of 20%, which has previously been felt to be a safe level of hemodilution, is associated with adverse perioperative and developmental outcomes in infants at 1 year.  However, it is important to note that bypass techniques very widely from surgeon to surgeon.  For example, many of the lesions which the authors in the current manuscript repair using techniques of deep hypothermic circulatory rest or low flow cardiopulmonary bypass would be performed at our institution with bicaval cannulation, continuous full flow cardiopulmonary bypass and mild-moderate hypothermia.  Regardless, this is a well designed study with interesting results, which should be taken in the context of the reader’s institutional management strategies.

 

 

 

May/June 2004 issue [25.3]

Morphometry of coronary capillaries in hypoplastic left heart syndrome

Salih C, Sheppard MN , Yen Ho S (2004) Ann Thorac Surg 77:903-7

 

Summary:  Eleven hearts from infants less than 2 months of age with either hypoplastic left heart syndrome (HLHS, n=11) or normal anatomy (n=4) were analyzed for their capillary anatomy.  Specimens were taken from both the right and left ventricles, and were stained with antibodies against von Willebrand’s.  Multiple measurements were then taken to analyze the mean and maximal diffusion distance between capillaries, as well as the variability in capillary spacing.  The results showed that the mean and maximal capillary spacing in both the abnormal left ventricle and “normal” right ventricle of the patients with HLHS were significantly higher when compared to controls. 

 

Editors (RGO) comments: While other studies have looked at the larger coronary arteries in HLHS, this is the first which addresses the coronary architecture.  It is unknown whether this increase in the mean and maximal capillary distribution is due to an increase in myocyte size, number, or an increase in extracellular material.  While the precise significance of these changes is unknown, these data do raise some interesting questions.  For example, there is renewed interest in the RV-to-PA conduit for supplying pulmonary blood flow in the Norwood operation, and one of the reported benefits is an improvement in coronary profusion.  Perhaps with the lower capillary density, the diastolic steal associated with the traditional modified Blalock-Taussig shunt may be particularly important. 

 

 

Results with the freestyle porcine aortic root for right ventricular outflow tract reconstruction in children.

 

Kanter KR, Fyfe DA, Mahle WT, Forbess JM, Kirshborn PM (2003) Ann Thorac Surg 76:1889-95

 

This manuscript reviews a single institution’s experience using the Medtronic Freestyle porcine aortic root for right ventricular outflow tract (RVOT) reconstruction in children.  There were 56 patients (mean age 11.8 years), who underwent RVOT reconstruction with the Freestyle root.  The most common diagnosis in half of the patients was tetralogy of Fallot.  All patients except one had undergone previous cardiac surgery (average 1.9 prior operations).  There were no deaths at a mean follow-up of 30 ± 20 months.  One patient developed mediastinitis and another was treated for endocarditis.  Insufficiency of the graft was rated as mild or none in 92%.  The calculated mean peak RVOT gradient by echocardiography was 19.7 ± 15.4 mmHg.  While the authors note that long term data are lacking, they feel that the Freestyle bioprosthesis for RVOT construction in children is an excellent choice. 

 

Editor (RGO) comments: The ideal conduit for RVOT reconstruction, which exhibits the characteristics of the lack of the need of anticoagulation, long term competence, freedom from the development of stenosis, and ultimately growth, remains elusive.  In this population of predominately older patients, the authors have demonstrated that the Freestyle bioprosthesis may be a useful addition to the armamentarium of the congenital heart surgeon.  Its final role in the care of these patients awaits further long-term studies.

 

 

Apolipoprotein E genotype and neurodevelopmental sequelae of infant cardiac surgery.

 

Gaynor JW, Gerdes M, Zackai EH, Bernbaum J, Wernovsky G, Clancy RR, Newman MF, Saunders AM, Heagerty PJ, D’Agostino J, McDonald-McGinn D, Nicolson SC, Spray TL, Jarvik GP (2003) J Thorac Cardiovasc Surg 126:1736-45

 

As the mortality of surgery for congenital heart disease has drastically declined in recent years, the importance of neurodevelopmental outcome has becoming increasingly important.  Apolipoprotein E (APOE) is an important regulator of cholesterol metabolism in the central nervous system (CNS).  There are three common isoforms of APOE (E2, E3, E4), which are encoded by three alleles (ε2, ε3, ε4).  Associations have been noted between the various alleles and Alzheimer’s, as well as recovery from CNS injury.  This prospective study of patient’s ≤ six months of age undergoing repair of congenital heart defect was performed to evaluate any association between APOE genotype and neurodevelopmental outcome (NDO).  NDO was evaluated at one year by using the Bayley Scales of Infant Development.  The one-year evaluation was performed on 244 patients, with adjustment for various perioperative covariates.  The primary finding was that APOE ε2 allele carriers had significantly lower Psychomotor Development Index scores at one year of age following infant cardiac surgery.

 

Editor’s (RGO) Comments: Neurodevelopmental outcome had become an area of increasing interest in patients following repair of congenital heart defects, particularly in infancy.  The finding that genetic polymorphism contributes to NDO, suggests a role for neuroresiliency in response to the multiple possible mechanisms of CNS injury during repair of congenital heart disease in infants.  A limitation of the study, that neurodevelopmental assessment at one year is not predictive of long term outcome, indicates the need for continued follow-up studies.  This limitation not withstanding, this manuscript shows an interesting and novel approach to understanding NDO in congenital heart disease. 

 

 

Role of magnetic resonance angiography in the diagnosis of major aortopulmonary collateral arteries and partial anomalous pulmonary venous drainage

 

Prasad SK, Soukias N, Hornung T, Khan M, Pennell DJ, Gatzoulis MA, Mohiaddin RH (2004) Circulation 109:207-214.

 

This prospective study evaluated 29 consecutive patients with an established or suspected diagnosis of multiple aortopulmonary collateral arteries (MAPCA) or partial anomalous pulmonary venous drainage (PAPVD).  All patients underwent cardiovascular magnetic resonance (CMR) and contrast-enhanced magnetic resonance angiography (MRA).  Sixteen patients (mean age 31.8) had evidence of MAPCAs.  There was 100% correlation between the CMR, MRA, and surgical or catheter-based evaluation of the MAPCAs.  In 36% of the cases, CMR/MRA provided additional clinically relevant information.  In all cases, MRA confirmed the presence or absence of central pulmonary arteries.  For patients with PAPVD (mean age 47.1 years), the site of drainage was identified in 85% (11/13).  In 3 patients (23%), MRA established a new diagnosis of PAPVD.  In 5 of 13 patients, the MRA data was considered diagnostic and subsequent catheter study was not performed.  In addition, phase-shift velocity mapping sequences can be used to quantify shunt. 

 

Editor (RGO) comments: CMR/MRA has shown promise as a diagnostic tool in congential heart disease.  Previous studies have shown its utility in diagnosing aortopulmonary collateral’s in pediatric patients.  In adult patients, echocardiography and sometimes cardiac catheterization fails to adequately define the anatomy.  This study demonstrates that CMR/MRA is a useful adjunct in the diagnosis of MAPCA and PAPVD.  In addition, magnetic residence imaging techniques avoid the need for radiation.  While these techniques have yet to supplant cardiac catheterization, their usage is likely to continue to increase in the future. 

 

 

Factors associated with impaired clinical status in long-term survivors of tetralogy of Fallot repair evaluated by magnetic resonance imaging

 

Geva T, Sandweiss BM, Gauvreau K, Lock JE, Powell AJ (2004) JACC 43:1068-74.

One hundred consecutive patients undergoing magnetic residence imaging (MRI) comprised the cohort for this study.  The patients had all previously undergone repair of tetralogy of Fallot (TOF) with pulmonary stenosis or atresia greater than ten years prior to the MRI.  Demographic and clinical data were retrospectively obtained from the patient’s medical records.  48% of the patients were in New York Heart Association (NYHA) functional class 1, 40% were in NYHA functional class 2 and 12% had class 3 symptoms.  MRI variables evaluated included left and right ventricular end diastolic volume (L/RVEDV), right and left ventricular end systolic volumes (L/RVESV), mass, stroke volumes, ejection fraction (EF), and quantification of pulmonary regurgitation (PR).  The degree of PR and the indexed RVEDV were not associated with impaired clinical function.  By multivariable analysis, a lower left ventricular EF and older age at TOF repair were the strongest independent factors associated with impaired clinical status.  With regard to the right ventricle, a lower right ventricular EF was the strongest independent factor associated with poor clinical performance.  The left ventricular EF correlated with the right ventricular EF.  While not associated with poor clinical condition or RV function, the degree of PR was related to the degree of RV enlargement.  While the study was not designed to determine the optimal timing for pulmonary valve replacement, the authors make several clinical observations.  These include that 1) all patients with RV ESV index ≥ 95ml/m2 RV dysfunction and all patients with LVESV index ≥ 50ml/m2 had LV systolic disfunction; 2) LV or RVEF is the strongest independent predictor of clinical status, with threshold values of less than 35% for the RV and less than 50% for the LV; and 3) patients who had their TOF repaired at an older age were more susceptible for having cardiac related symptoms. 

 

Editor (RGO) comments: As with the previous review, magnetic residence imaging is being used with increasing frequency in the management of both adults and children with congenital heart disease.  Unlike previous studies, which have shown that the degree of PR is directly related to a poor clinical status, these findings indicate that it is the degree of RV and LV dysfunction, which is independently related to a poor clinical status.  These findings are not necessarily mutually exclusive to the previous findings of other studies, as there is most likely a complex inter-relation between the degree of PR, the function of the LV and RV, and the patient’s clinical condition.  In addition, the high correlation between LVEF and RVEF suggests an important interaction between the right and left ventricles.  While not a primary aim of the study, the observations relating to the timing for pulmonary valve replacement provides some data to aide in the decision making process of this controversial topic. 

 

 

Long-term outcome (up to 15 years) of balloon angioplasty of discrete native coarctation of the aorta in adolescents and adults

 

Fawzy ME, Awad M, Hassan W, Kadhi YA, Shoukri M, Fadley F (2004) JACC 43:1062-7.

 

This manuscript reports the longest follow-up published of a series of adolescent and adult patients treated with balloon angioplasty for a discrete native coarctation.  Of the 68 patients presenting with coarctation to this institution, 6 were referred for surgery.  The remaining 54 underwent balloon angioplasty.  The technique was as previously reported, and did not entail the implantation of a stent.  Of the 54 patients, one developed a dissection, required immediate surgical repair and was excluded from analysis.  Two patients were living abroad and one patient refused cardiac catheterization.  The remaining 49 patients underwent a repeat catheterization and MRI one year following their balloon angioplasty.  They subsequently underwent repeated MRI every year with a mean follow-up of 9.1 ± 4.4 years.  There were no immediate or late deaths in the study.  The immediate results showed a decrease in the mean gradient from 66 ± 23mmHg to 10.8 ± 7mmHg (p < 0.0001).  Four patients had a suboptimal initial outcome as defined by a residual gradient greater than 20mmHg.  Three of the four underwent redilation at six months with a good result.  The last patient underwent surgical repair.  One-year follow-up catheterization was performed in 50 of the patients.  The mean gradient across the coarctation had further decreased to 6.2 ± 6mmHg.  Aneurysms developed in four of the patients (7.8%).  Three of the patients have had stable aneurysms, and the fourth required surgical repair.  In long-term follow-up, the MRI revealed no significant changes in the diameter of the aorta, the site of the coarctation, and no additional aneurysms.  Blood pressure was normal without medication in 31 patients (63%). 

 

Editor (RGO) comments: This long-term study would suggest that balloon angioplasty for discrete native coarctation in adolescents and adults is a viable treatment alternative to the traditional surgical approach.  While the rate of aneurysm formation is significantly higher than that reported for appropriate surgical methods, this must be balanced with the short and potentially long-term morbidity of an open repair.  The role of stents in adult and adolescent coarctations remains somewhat controversial.  Overall, this group reported excellent results without the use of stents, suggesting that they are unnecessary.

 

 

July/August 2004 issue [25.4]

Alteration of the critical arteriovenous oxygen saturation relationship by sustained afterload reduction after the Norwood procedure.

 

Hoffman GM, Tweddell JS, Ghanayem NS , Mussatto KA, Stuth EA, Jaquiss RD , Berger S. (2004) J Thorac Cardiovasc Surg 127:738-45.

 

Seventy-one consecutive neonates undergoing the Norwood procedure with and without phenoxybenzamine during cardiopulmonary bypass were studied.  Sixty-two of the patients had received phenoxybenzamine (0.25mg per kg) and 9 had not.  The patients were subsequently monitored for systemic oxygen saturation (SaO2) and for continuous systemic venous saturation (SvO2) by a continuous oximetric catheter placed into the superior vena cava.  The authors study hypothesis was that afterload reduction with phenoxybenzamine would modify the SvO2/SaO2 relationship by preventing deterioration of systemic oxygen delivery at high SaO2.  In control patients, SvO2 peaked at a SaO2 of 77%.  SvO2 was adversely effected at a SaO2 >85% or <70% (p<0.01), and arterial venous oxygen content difference increased at a SaO2 >80% (p<0.001).  In the patients who received phenoxybenzamine during the Norwood operation, SvO2 increased linearly at a SaO2 >65% (p<0.001), and the arterial venous oxygen contents difference remained constant at all SaO2 levels (p=NS).  SvO2 was higher and arterial venous oxygen content was lower across the entire range of SaO2 in those patients receiving phenoxybenzamine, when compared to controls (p<0.0001).  The authors conclude that the use of systemic afterload reduction with phenoxybenzamine eliminated the systemic hypo-perfusion associated with high levels SaO2. 

 

Editor (RGO) comments:  As noted in the article by Bradley and associates reviewed in this section, the traditional management of the postoperative Norwood patient has involved controlling the SaO2.  This treatment method was confirmed in this study in control patients not receiving afterload reduction with phenoxybenzamine, in whom increasing SaO2 > 85% resulted in a decreased SvO2 and an increase in the arterial venous oxygen content difference.  In the patients receiving phenoxybenzamine, a long acting alpha-blocker, an increase in SaO2 lead to an improvement in SvO2 and arterial venous oxygen content difference.  While Bradley and colleagues do not specify whether they used alpha-blockade on bypass, 9 of the 14 neonates evaluated in that study were receiving Milrinone, potentially explaining the similar results. 

 

 

 

Determinants of mortality and type of repair in neonates with pulmonary atresia and intact ventricular septum.

 

Ashburn DA, Blackstone EH, Wells WJ, Jonas RA, Pigula FA, Manning PB, Lofland GK, Williams WG, McCrindle BW, Members for the Congenital Heart Surgeons Society (2004) J Thorac Cardiovasc Surg 127:1000-8.

 

Between 1987 and 1997, 400 neonates with pulmonary atresia and intact ventricular septum were entered into a prospective study by 33 institutions.  Six end states were evaluated, which included two ventricle repair, Fontan, 1.5 ventricle repair, heart transplantation, death before reaching definitive repair, and alive without definitive repair.  Multi-variable analysis was used to define parameters predictive of attaining each of these end states.  Survival at 1 month, 6 months, 1 year, 5 years, and 15 years after was 80%, 70%, 68%, 60% and 58%, respectively.  Survival improved across the study period, with 5-year overall survival at in 1987, 1992, and 1997 improving from 49% to 63% and 79% over the time intervals.  Incremental factors associated with reaching each of the five end points are presented for each category.  Overall, patient-related factors primarily included adequacy of right-sided heart structures, degree of coronary circulation abnormalities, low birth weight, and tricuspid valve regurgitation.  In addition, certain institutions were associated with the various outcomes.  In conclusion, the authors were able to define characteristics which were predictive of the various types of definitive repair.  In the current era, 85% of neonates in the study were found to have successfully reached a definitive surgical end point, including two ventricle repair in approximately 50%. 

 

Editor (RGO) comments:  Pulmonary atresia with intact ventricular septum continues to be one of the more difficult management problems in congenital heart disease.  Further more, it does not lend itself to easy study as the lesion comprises a wide spectrum of anatomic variation.  This very large multi-institutional study from the Congenital Heart Surgeons Society was able to define certain characteristics of neonates with pulmonary atresia and intact ventricular septum, which may be used to predict definitive repair.  These parameters may be useful in developing management strategies for the individual patient.  In addition, the authors found certain institutions to be predictive of better outcome.  While this may be due to local resources, broader the application of these institution’s management protocols may help other institutions achieve similar results.  Overall, it is encouraging to see that outcomes continue to improve across time for this challenging group of patients.

 

 

 

 

Early cavopulmonary anastomosis in very young infants after the Norwood procedure:  Impact on oxygenation, resource utilization, and mortality.

 

Jaquiss RDB, Ghanayem NS, Hoffman GM, Fedderly RT, Cava JR, Mussatto KA, Tweddell JS (2004) J Thorac Cariovasc Surg 127:982-9.

 

Eighty-five consecutive patients undergoing a stage II palliation were divided into two groups based upon the age at the time of the cavopulmonary anastomosis.  Group 1 (n=33) were patients less than four months of age at the time of operation.  These patients were compared to group 2 (n=52), which was comprised of patients greater than four months of age at the time of operation.  As expected, group 1 patients were significantly younger (94 versus 165 days, p<0.001), and smaller (4.8kg versus 5.8kg, p<0.001).  There was no difference in preoperative oxygen saturation between the groups.  In the immediate postoperative period, oxygen saturation was lower in group 1 compared to group 2 (75% versus 81%, p<0.001).  However, there was no difference between the two groups at the time of discharge (79% versus 80%).  Group 1 patients required longer periods of ventilation, longer ICU stays, longer hospitalization, and longer plural drainage.  Hospital survival was 100% in both groups, and 12-month actuarial survival was 96% in both groups, as well.

 

Editor (RGO) comments:  These data suggest that while younger patients (less than four months of age) may have a somewhat more prolonged and complex hospital course following early cavopulmonary connection, they have equivalent survivals at hospital discharge and 12 months.  The findings are in agreement with previous publications from our institution and other authors.  One may question the impetus for an early cavopulmonary anastomosis, as it results in a more complex postoperative course.  However, the shunt dependent physiology following the Norwood operation is an inherently unstable circulation, with significant interstage attrition.  In addition, in a previous publication from the same group (Ghamayem NS [2003] J Thorac Cardiovasc Surg 126:1367) demonstrated a plateau in growth in the 5th and 6th months following the Norwood operation, suggesting that waiting the additional two months for increased somatic growth may not be warranted. 

 

 

 

Is Extended Arch Aortoplasty the Operation of Choice for Infant Aortic Coarctation?  Results of 15 Years’ Experience in 181 Patients.

 

Wood AE, Javadpour H, Duff D, Oslizlok P, Walsh K (2004) Ann Thorac Surg 77:1353-8.

 

This series reviews 181 patients less than one year-of-age undergoing repair for coarctation of the aorta (CoA) from a single institution.  Median age was 13.5 days (range; 1-300 days) and a median weight of 3.7kg (range; 0.85-10.5kg).  One hundred thirty-five of these infants (74%) were neonates.  All patients were assessed by right arm/left leg Dynamap pressures preoperatively and in follow-up.  The follow-up was complete in all patients at a median of 7.5 years (range; 6 months-16 years).  The patients were subdivided into groups.  Isolated CoA was considered group one, CoA plus ventricular septal defect was group two and complex congenital heart disease was group three.  The overall hospital/30 day mortality was 0.5%, with all the early mortalities occurring in group three.  Late death occurred in 15 patients (8.3%), 3 in group two and 12 in group three.  Re-coarctation, as defined by a clinical gradient of greater than 20mmHg, occurred in 4 patients (2.2%).  All 4 patients had a gradient of greater than 10mmHg postoperatively.  All 4 patients were treated successfully balloon dilatation and remained free of recurrence at a median follow-up of 90 months. 

 

Editor (RGO) comments:  The treatment of coarctation in the aorta remains an area of some controversy, with respect to both surgical technique and timing of repair.  This series of patients reviews a single institutions experience with repair at an early age using the technique of extended resection and end-to-end anastomosis.  This technique has the advantage of resecting the area of the coarctation and aortic isthmus, which is invariably involved.  In addition, the vast majority of patients presenting in infancy have some degree of hypoplasia of the distal arch.  The described technique has the advantage of addressing all of these issues.  In addition, earlier repair has the potential advantage to decrease the potential long-term complication of hypertension.  This report, in conjunction with several other recent reports, support that early repair of coarctation using the technique of extended resection with end-to-end anastomosis is the treatment of choice for the infant presenting with coarctation of the aorta.

 

 

 

Modification to the Fontan procedure for the prophylaxis of intra-atrial reentrant tachycardia:  Short-term results of a prospective randomized blinded trial.

 

Collins KK, Rhee EK, Delucca JM, Alexander ME, Bevilacqua LM, Berul CI, Walsh EP, Mayer JE, Jonas RA, del Nido PJ, Triedman JK (2004) J Thorac Cardiovasc Surg 127:721-9.

 

This manuscript reviews a prospective, randomized, evaluator-blinded trial in 42 patients undergoing a lateral tunnel Fontan.  Patients were randomized to receive an atrial incision and cryoablation from the inferior portion of the right atriotomy to the right atrioventricular valve annulus.  There were no differences between the study and control groups with respect to demographics.  Patients underwent short-term evaluation, which revealed a lower conduction time across the incision area in the intervention patients.  There was no significant difference in the incidence of spontaneous or inducible intra-atrial reentrant tachycardia (IART) between the two groups.  While both groups had a high percentage of sinus node dysfunction in the initial postoperative period, this largely resolved by hospital discharge, with 10% incidence in the study group and 5% in the control group (p=NS).  There was no difference in complication rates between the two groups.  The authors conclude that the interventional arterial incision and cryoablation lesion used in an effort to reduce IART in this group of Fontan patients was feasible and safe.  While short-term results showed a low incidence of IART and both patient groups, long-term follow-up is necessary access the ethicacy of the interventional incision. 

 

Editor (RGO) comments:  IART remains a frequently complication following the Fontan operation with estimates of prevalence as high as 50% by ten years.  Current strategies for arrhythmia management primarily consists of management of  the IART.  There have been few attempts to surgical prophylaxes of IART.  As with a previous study performed at our institution using a similar incision (Law IH [2000] PACE 23:598), no short-term benefit was demonstrated in the prevention of IART.  However, as the incision addresses one of the most common areas for the propagation of IART, long-term follow-up will be required to evaluate the true impact of this prophylactic incision on the incidence of IART in the Fontan patient. 

 

 

 

Outcome of aortic valve repair in children with congenital aortic valve insufficiency.

 

Hasaniya N, Gundry SR, Razzouk AJ, Mulla N, Bailey LL (2004) J Thorac Cardiovasc Surg 127:970-4.

 

This retrospective review details the outcomes for 17 patients younger than 17 years of age undergoing aortic valve repair for congenital aortic regurgitation at a single institution.  The mean age for these patients was 8.1 +/- 3.7 years.  The underlying anatomy was bicuspid aortic valve in 6 (35%) and a tricuspid valve in 11 (65%).  The aortic regurgitation was moderate in 2 patients and severe in 15 patients.  The aortic regurgitation was graded echocardiographically as mild when the regurgitant jet reached 25% of the distance from the aortic valve to the LV apex, moderate when the jet reached 50% of this distance and severe when the jet reached more than 50% of this distance.  The indication for surgery was the presence of the moderate-severe regurgitation, as well as progressive increase in LV dimension.  Valve repair was tailored to the individual patient, but generally consisted of leaflet plication with commissural re-suspension, leaflet thinning, release of thickened leaflets, partial commissure closure, triangular resection and repair of redundant leaflets, or repair of torn/perforated leaflets.  Immediate follow-up showed that 15 patients (89%) had none-mild regurgitation and 5 patients (11%) had moderate regurgitation.  Follow-up ranged from 1-11 years with a mean of 5.3 +/- 2.4 years.  Sequential echocardiographic follow-up revealed mild aortic regurgitation has been maintained in 3 of the 17 patients (17.6%).  Six patients (35.2%) have moderate aortic regurgitation.  Eight of seventeen cases (47.1%) required re-operation for aortic regurgitation from 0.5-73 months after the original operation (mean 18.9 months).  There were no deaths in either the initial repair or at the secondary operation. 

 

Editor (RGO) comments:    While the surgical treatment of aortic stenosis has resulted in a track record of durability, repair for dominant congenital regurgitation has been less satisfactory.  These disappointing results also stand in contrast to valve repair for rheumatic, traumatic, or acquired aortic valve regurgitation, such as in this setting of aortic dissection.  This report is consistent with the other series of patients undergoing aortic valve repair for congenital aortic regurgitation, which generally show a 5-year failure rate of 50% and a 10-year failure rate of 75%.  While newer repair techniques and improvement in the understanding of aortic valve anatomy may improve results over time, current results for the repair of the congenitally regurgitant aortic valve remain disappointing.

 

 

 

 

Preoperative Brain Injury in Newborns With Transposition of the Great Arteries.

 

Miller SP, McQuillen PS, Vigneron DB, Glidden DV, Barkovich AJ, Ferriero DM, Hamrick SEG, Azakie A, Karl TR (2004) Ann Thorac Surg 77:1698-706.

 

The study population consisted of ten term newborns with transposition of the great arteries (TGA) undergoing an arterial switch operation with full-flow cardiopulmonary bypass.  The patients underwent preoperative magnetic residence imaging (MRI) and 3-dimensional magnetic resonance spectroscopic imaging (MRSI).  Compounds measured using MRSI included lactate/choline (a marker of cerebral oxidated metabolism) and N-acetylaspartate (NNA)/choline (a marker of cerebral metabolism and density).  Of the infants studied, four were found to have a preoperative injury on MRI.  Only one new lesion was detected post-operatively.  Five normal term neonates were used as controls.  The MRSI for lactate/choline was higher in newborns with TGA compared to controls (P<0.0001).  This difference was significant even in those patients without preoperative brain injury.  Lactate/choline decreased after surgery in the patients with TGA, suggesting an improvement in their cerebral oxidative metabolism following the arterial switch operation.  In half of the newborns undergoing operation, NNA/choline decrease indicating detrimental effects in the intra-operative or immediate postoperative period.  Interestingly, the four newborns with preoperative brain injury demonstrated MRI evidence of embolic phenomenon.  The same four newborns had all undergone preoperative balloon atrial septostomy, possibly suggesting a etiologic role of the septostomy.  The authors conclude that abnormal brain metabolism and neurological injury was observed preoperatively in newborns with TGA, and that neurologic abnormalities were not solely related to the operative course. 

 

Editor (RGO) comments:  This study of newborns with TGA revealed preoperative brain injury in 40% of patients (4/10).  This observation is consistent with previous studies of newborns with a variety of types of lesions, which demonstrated preoperative ischemic lesions in 24%.  In contrast to that same study, this manuscript identified very few patients with new postoperative injuries.  This is likely due to the fact that in the previous study 88% of the patients underwent deep hypothermic circulatory arrest, at a median of 50 minutes.  While the observation of the relationship between balloon atrial septostomy and preoperative ischemic injury potentially warrants further investigation, it would also be important to know the patients clinical history and mode of presentation, and how that may relate to preoperative injury to the brain.  Overall, this manuscript provides further evidence that neonates with congenital heart disease are at significant risk for both pre-operative and operative neurologic injury.  A further understanding of the etiologic factors involved will be important in prevention of injury, as well as identifying those patients at high risk who may require special protective strategies or early intervention. 

 

 

 

Redefining the impact of oxygen and hyperventilation after the Norwood procedure.

 

Bradley SM, Atz AM, Simsic JM (2004) J Thorac Cardiovasc Surg 127:473-80.

 

Fourteen neonates were prospectively studied 1-3 days after a Norwood procedure for the impact of varying levels of the fraction of inspired oxygen (FiO2) and hyperventilation.  Patients were then exposed to two interventions in random order consisting of either a fraction of inspired oxygen (FiO2) of 1.0 or hyperventilation to a mean rate of 30 breaths per minute.  Patient’s mixed venous saturation and peripheral oxygen saturation were monitored.  Oxygen excess factor (systemic oxygen delivery/oxygen consumption) was used as an indicator of systemic oxygen delivery.  The results revealed high levels of FiO2 produced significant increases in systemic saturation (90% versus 80%, p<0.01), mixed venous saturation (54% versus 44%, p<0.01), and oxygen excess factor (2.6% versus 2.3%, p<0.01).  There was no change in arterial venous saturation difference or blood pressure.  Hyperventilation resulted no changes in any of these parameters.  The authors conclude that management protocols aimed at minimizing FiO2 and controlling ventilation may not be warranted.

 

Editor (RGO) comments:  The postoperative management after the Norwood procedure is aimed at optimizing systemic oxygen delivery.  In an effort to increase systemic flow, it is common practice to minimize the FiO2 and avoid hyperventilation in an effort to avoid pulmonary over circulation.  While this study evaluated only a limited number of patients at single levels of high FiO2 and hyperventilation, it would suggest that increasing FiO2 may be useful in those patients with poor systemic oxygen delivery in the immediate postoperative period following the Norwood operation.