Outcome after operations for pulmonary atresia with intact ventricular septum

Outcomes of infants with pulmonary atresia with intact ventricular septum listed for heart transplantation: A multi-institutional study

BACKGROUND

Management of infants with pulmonary atresia/intact ventricular septum (PA/IVS) is variable. Because of higher mortality in more severe forms, heart transplant (HT) is an acceptable approach, but waitlist and post-transplant outcomes are unclear. This study compared outcomes of infants with PA/IVS vs. other single ventricle (SV) anatomies listed for HT.

METHODS

Data from the Pediatric Heart Transplant Society (1993-2018) were analyzed for survival and risk factors for mortality.

RESULTS

Of 1617 SV infants, 300 had PA/IVS (19%) and 1317 had other SV (81%). Overall, 1-, 5-, and 10-year survival was higher among PA/IVS (74%, 65%, 61%) versus other SV infants (62%, 54%, 50%, p = .004). While waitlist mortality was similar between groups (p = .09), PA/IVS was an independent predictor of improved waitlist survival (HR 0.68, p = .03), and PA/IVS infants had higher incidence of waitlist removal (8% vs. 5.5%, p = .03), most commonly for being "too well." Post-transplant survival was superior among PA/IVS versus other SV infants (1- and 5-year survival 93% and 81% vs. 80% and 71%, p < .0001). Risk factors for PA/IVS waitlist mortality (2008-2018) included extracorporeal membrane oxygenation and mechanical ventilation. Prior aortopulmonary (AP) shunt among PA/IVS infants was associated with improved waitlist survival.

CONCLUSIONS

Overall survival among PA/IVS infants listed for HT exceeds that of other SV infants with PA/IVS identified as an independent predictor of improved waitlist and post-transplant survival. Prior AP shunt among listed PA/IVS infants was associated with improved waitlist outcomes, though, which may reflect a listing selection bias.

Procedural Outcomes of Pulmonary Atresia Intact Ventricular Septum in Neonates: A Multicenter Study

BACKGROUND

Multicenter contemporary data describing short-term outcomes following initial interventions of neonates with pulmonary atresia intact ventricular septum (PA-IVS) are limited. This multicenter study aims to describe characteristics and outcomes of PA-IVS neonates following their initial catheter or surgical intervention and identify factors associated with major adverse cardiac events (MACE).

METHODS

Neonates with PA-IVS who underwent surgical or catheter intervention between 2009-2019 in 19 centers were reviewed. Risk factors for MACE, defined as cardiopulmonary resuscitation, mechanical circulatory support, stroke, or in-hospital mortality, were analyzed using multivariable logistic regression model.

RESULTS

We reviewed 279 neonates: 79 (28%) underwent right ventricular decompression, 151 (54%) underwent systemic-to-pulmonary shunt or ductal stent placement only, 36 (13%) underwent right ventricular decompression with shunt or ductal stent placement, and 11 (4%) underwent transplantation. MACE occurred in 57 patients (20%): 26 (9%) received mechanical circulatory support, 37 (13%) received cardiopulmonary resuscitation, 16 (6%) suffered stroke, 23 (8%) died. The presence of two major coronary artery stenoses (adjusted OR: 4.99; 95% CI: 1.16-21.39) and lower weight at first intervention (adjusted OR: 1.52, 95% CI: 1.01-2.27) were significantly associated with MACE. Coronary ischemia was the most frequent presumed mechanism of death (n=10).

CONCLUSIONS

In a multicenter cohort, one in five neonates with PA-IVS experienced MACE following their initial intervention. Patients with two major coronary artery stenoses or lower weight at time of initial procedure were most likely to experience MACE and warrant vigilance during pre-intervention planning and post-intervention management.

The Use of Chronic Total Occlusion (CTO) Wires for Perforation of Atretic Pulmonary Valve; Two Centers Experience

Pulmonary valve atresia with intact ventricular septum (PA-IVS) can be treated either surgically or transcatheterly for eligible patients. Perforation of pulmonary valves using chronic total occlusion (CTO) guidewires has been reported as an alternative to radiofrequency (RF) perforation. We sought to report our experience with CTO guidewires for perforation of atretic pulmonary valves and subsequent balloon dilatation (with or without patent ductus arteriosus stenting) in patients with PA-IVS from two centers. A retrospective study was carried out on PA-IVS patients who underwent intervention between March 2014 and September 2019, in which CTO guidewire was employed for pulmonary valve perforation. A total of 26 patients were identified. The median age and weight of the patients were 5.2 days (range 1-21 days) and 3.1 kg (range 2.2-3.8 kg), respectively. All patients were situs solitus, except one patient with left atrial isomerism. The right ventricle (RV) morphology was bipartite in 22/26 patients and tripartite in 4/26 patients. Before the procedure, the mean saturation was 76% (range 70-86%) while the patients were under prostaglandin infusion. The pulmonary valve perforation attempt was performed with the Asahi Conquest Pro 9 CTO wire (n = 6) or Asahi Pro 12 CTO wire (n = 18) and/or Asahi Miracle CTO wire (n = 2). The procedure was successful in 20/26 (77%) patients using CTO wires. We analyzed the efficiency of CTO wire based on the subtypes: Conquest Pro 9 in 6/6 (100%) patients, Conquest Pro 12 in 12/18 (67%) patients, and Miracle in 2/2 (100%) patients. Before CTO wire usage in 3 patients, radiofrequency (RF) perforation was unsuccessful. Among these 3 patients, pulmonary valve perforation was successful in 2 patients with CTO wire; hence, in the remaining patient, perforation was also unsuccessful with CTO wire. After CTO wire perforation was unsuccessful in 6 patients, RF perforation was attempted in 3 patients (2 successful attempts and 1 unsuccessful attempts), and one patient as referred to surgery. Desaturation was persistent in 19 cases, which necessitated ductus arteriosus stenting. Early procedural complication was observed in 3/26 (11%) patients. Two of these patients had vascular complications due to the sheath, which was treated with heparin infusion and streptokinase, and the remaining patient had sudden bradycardia and cardiac arrest during the procedure and did not respond to cardiac resuscitation. CTO wires should be keep in mind for atretic pulmonary valve perforation as a first choice or when RF perforation is unsuccessful.

Survival With Respect to Morphology in Pulmonary Atresia and Intact Ventricular Septum in Sweden

BACKGROUND

Patients born with pulmonary atresia and intact ventricular septum represent a challenge to pediatric cardiologists. Our objective was to study changes in survival with respect to morphology in all children born with pulmonary atresia and intact ventricular septum in Sweden during 36 years.

METHODS

A retrospective, descriptive study based on medical reports and echocardiographic examinations consisting of those born between 1980 and 1998 (early group) and those born between 1999 and 2016 (late group).

RESULTS

The cohort consists of 171 patients (early group, n = 86 and late group, n = 85) yielding an incidence of 4.35 and 4.46 per 100,000 live births, respectively. One-year survival in the early group was 76% compared to 92% in the late group (P = .0004). For patients with membranous atresia, one-year survival increased from 78% to 98%, and for muscular pulmonary atresia, from 68% to 85%. In patients with muscular pulmonary atresia and ventriculocoronary arterial communications, there was no significant increase in survival. Risk factors for death were being born in the early time period hazard ratio (HR), 6; 95% CI (2.33-14.28) P = .0002, low birth weight HR, 1.26; 95% CI (1.14-1.4) P < .0001 and having muscular pulmonary atresia HR, 3.74; 95% CI (1.71-8.19) P = .0010.

CONCLUSION

The incidence of pulmonary atresia and intact ventricular septum remained unchanged during the study period. Survival has improved, especially for patients with membranous pulmonary atresia, while being born with muscular pulmonary atresia is still a risk factor for death. To further improve survival, greater focus on patients with muscular pulmonary atresia and ventriculocoronary arterial communications is required.

Long-term outcomes of single-ventricle palliation for pulmonary atresia with intact ventricular septum: Fontan survivors remain at risk of late myocardial ischaemia and death

OBJECTIVES

The specific outcomes of patients with pulmonary atresia with intact ventricular septum late after Fontan palliation are unknown. Patients with smaller right ventricles and myocardial sinusoids are known to have worse survival in the first years of life. Whether the potential for coronary ischaemia affects the long-term outcomes of these patients after Fontan palliation is still unknown.

METHODS

All patients with pulmonary atresia with intact ventricular septum who underwent the Fontan procedure from 1984 to 2016 in Australia and New Zealand were identified, and preoperative, perioperative and follow-up data were collected.

RESULTS

Late follow-up data were available for 120 patients. The median length of follow-up after the Fontan procedure was 9.1 years (interquartile range 4.2-15.4 years). Late death occurred in 9% of patients (11/120). Six were sudden, unexpected deaths; 4 of those occurred in patients known to have right ventricle-dependent coronary circulation (RVDCC). Those with RVDCC had a higher incidence of sudden death (4/20 vs 2/100; P = 0.007). RVDCC was associated with late death (P = 0.01) and the development of myocardial ischaemia after Fontan completion (P < 0.001). The 10-year survival rate was 77% (95% confidence interval 56-100%) for patients with RVDCC vs 96% (95% confidence interval 92-100%) for patients without RVDCC.

CONCLUSIONS

Long-term survival of patients with pulmonary atresia with intact ventricular septum after the Fontan procedure is excellent, but patients with RVDCC remain susceptible to coronary ischaemia and sudden death. Closer surveillance and investigation for exercise-induced ischaemia may be necessary.

Long-term outcomes after intervention for pulmonary atresia with intact ventricular septum

OBJECTIVE

Pulmonary atresia with intact ventricular septum (PA/IVS) can be treated by various operative and catheter-based interventions. We aim to understand the long-term transplant-free survival of patients with PA/IVS by treatment strategy.

METHODS

Cohort study from the Pediatric Cardiac Care Consortium, a multi-institutional registry with prospectively acquired outcome data after linkage with the National Death Index and the Organ Procurement and Transplantation Network.

RESULTS

Eligible patients underwent neonatal surgery or catheter-based intervention for PA/IVS between 1982 and 2003 (median follow-up of 16.7 years, IQR: 12.6-22.7). Over the study period, 616 patients with PA/IVS underwent one of three initial interventions: aortopulmonary shunt, right ventricular decompression or both. Risk factors for death at initial intervention included earlier birth era (1982-1992), chromosomal abnormality and atresia of one or both coronary ostia. Among survivors of neonatal hospitalisation (n=491), there were 99 deaths (4 post-transplant) and 10 transplants (median age of death or transplant 0.7 years, IQR: 0.3-1.8 years). Definite repair or last-stage palliation was achieved in the form of completed two-ventricle repair (n=201), one-and-a-half ventricle (n=39) or Fontan (n=96). Overall 20-year survival was 66%, but for patients discharged alive after definitive repair, it reached 97.6% for single-ventricle patients, 90.9% for those with one-and-a-half ventricle and 98.0% for those with complete two-ventricle repair (log-rank p=0.052).

CONCLUSIONS

Transplant-free survival in PA/IVS is poor due to significant infantile and interstage mortality. Survival into early adulthood is excellent for patients reaching completion of their intended path independent of type of repair.

Controversy About a High-Risk and Innovative Fetal Cardiac Intervention

A 20-week-old fetus was diagnosed with critical pulmonary valve stenosis. Given the ultrasound findings, the outcome was difficult to predict. The fetal cardiologists discussed the possibility of a pulmonary valvuloplasty (an experimental procedure) with the parents, wherein the fetal right ventricle would be punctured with a long 18G needle, and through it, a wire advanced across the pulmonary valve, allowing for balloon dilation of the valve. The experimental procedure had been performed at a handful of centers. There were some reports of success. The parents sought an opinion at one of the referral centers that had tried the procedure. The doctors there recommended against it. The doctors at the original center were unsure whether they should try the procedure. The parents wanted it. In this ethics rounds, doctors and the parents discuss the arguments for and against a high-risk, innovative in utero procedure.

Assessing the borderline ventricle in a term infant: combining imaging and physiology to establish the right course

PURPOSE OF REVIEW

The purpose of this review is to describe the challenges associated with the diagnosis and treatment of children with borderline ventricles. A borderline ventricle is one in which there is concern that it will not be able to support its circulation. If a biventricular repair is attempted and fails, outcome is often poor. Thus, this early decision is important.

RECENT FINDINGS

For the borderline right ventricle, options to add an additional source of pulmonary blood flow make the surgical strategy a bit more flexible than for patients with a borderline left ventricle. In general, outcome for a so-called one and one-half ventricle repair are generally good, though the long-term outcome and the effects of this physiology on lifelong exercise performance and quality of life remain to be seen. For the small left ventricle, often multiple surgeries are required to 'force' blood into the left ventricle and potentially help it grow. Though this strategy is successful in some, in others it results in significant residual cardiac issues including pulmonary hypertension.

SUMMARY

Determining whether a patient will be better off in the long term with a marginal biventricular repair versus a Fontan circulation remains one of the most difficult problems in the field of pediatric cardiology and cardiac surgery.

Transcatheter perforation of atretic pulmonary valve by the stiff end of a coronary wire in neonates with pulmonary atresia with intact ventricular septum: A solution in developing countries

Objectives

To evaluate the safety of using the stiff end of a coronary wire to perforate an atretic pulmonary valve (PV) in patients with pulmonary atresia with intact ventricular septum (PAIVS).

Background

Radiofrequency perforation is an accepted modality to perforate the PV in patients PAIVS. However, the high cost precludes its widespread use.

Patients and methods

This is a single-center experience that spanned from March 2013 to January 2016 and involved 13 neonates who were severely cyanotic with PAIVS and with ductal-dependent pulmonary circulation. The stiff end of a coronary wire was used to perforate the atretic PV anterogradely, followed by balloon pulmonary valvuloplasty.

Results

The mean age of patients was 3.9 ± 2.7 days and their mean weight was 2.8 ± 0.19 kg. The mean oxygen saturation was 77.1 ± 3.2%. All had membranous pulmonary atresia, with patent infundibulum and tripartite right ventricle. The valve was successfully perforated in 11 out of 13 patients. Death occurred in two patients (15.4%) owing to heart failure and sepsis. Patent ductus arteriosus stenting was performed 2 days after the procedure in one patient because of cyanosis followed by one and half ventricle repair at of age 5 months. Two patients (15.4%) had one and a half ventricle repair at age of 5 months and 6 months owing to insufficient anterograde pulmonary flow. Two patients (15.4%) underwent second intervention with balloon dilatation of the valve. The remaining seven patients (53.8%) had no further intervention. Two cases (15.4%) had femoral artery thrombosis treated with streptokinase. The mean duration of follow-up was 13.17 ± 7 months. There was significant improvement in the degree of tricuspid incompetence. There was a significant growth in the tricuspid valve annulus during the follow-up (the mean Z score increased from −0.8 ± 0.9 to 0.1 ± 0.9) (p = 0.003). There was also a significant increase in the tricuspid valve annulus/mitral valve annulus ratio as its mean increased from 0.73 ± 0.10 to 0.86 ± 0.11 during follow-up (p < 0.001).

Conclusion

Perforation of the atretic PV in selected cases with membranous atresia and patent infundibulum using the stiff end of a coronary wire is an effective alternative to using radiofrequency perforation.

Pulmonary Atresia With an Intact Ventricular Septum: Preoperative Physiology, Imaging, and Management

Pulmonary atresia with intact ventricular septum (PA-IVS) is a rare complex cyanotic congenital heart disease with heterogeneous morphological variation. Prenatal diagnosis allows for developing a safe plan for delivery and postnatal management. While transthoracic echocardiography allows for detailed delineation of the cardiac anatomy, additional imaging modalities such as computed tomography, magnetic resonance imaging, and catheterization may be necessary to further outline features of the cardiac anatomy, specifically coronary artery anatomy. The size of the tricuspid valve and right ventricular cavity as well as the presence of right ventricle–dependent coronary circulation help to dichotomize between biventricular repair versus univentricular palliation or heart transplantation, as well as predicting the expected survival. The delineation and understanding of these features help to dictate both medical and surgical management.

Prenatal Echocardiographic Predictors of Postnatal Management Strategy in the Fetus with Right Ventricle Hypoplasia and Pulmonary Atresia or Stenosis

Fetuses with pulmonary atresia or pulmonary stenosis with intact ventricular septum manifest variable degrees of right ventricle hypoplasia and inadequacy. We studied the relationship between prenatal echocardiographic parameters and their progression through gestation as potential predictors of postnatal single-ventricle or two-ventricle care strategy. Serial fetal echocardiograms of pulmonary atresia (n = 28) or severe pulmonary stenosis (n = 8) and intact ventricular septum were reviewed. Measurements included tricuspid valve and mitral valve diameter and Z scores, degree of tricuspid regurgitation, presence of subaortic stenosis, presence of coronary artery fistulae, and Doppler pulsatility indices in middle cerebral and umbilical artery. Data were compared between first and last fetal studies. Subjects were divided based on postnatal course of single- or two-ventricle repair. Tricuspid valve size of those destined for single ventricle is smaller than of those destined for a two-ventricle repair at first study (26w, Z score -4.22 v -1.83, p < 0.001) and at final study (35w, -4.94 v -1.42, p < 0.001). Tricuspid valve and right ventricle grow in those destined for two ventricle, but not single-ventricle palliation. Tricuspid valve Z score = -3 at first or last study discriminated between single- or two-ventricle repair, except in two unusual cases with significant subaortic stenosis. Tricuspid valve Doppler-derived parameters of middle cerebral artery and umbilical artery did not distinguish between groups. In the fetus with pulmonary atresia or stenosis and intact ventricular septum, tricuspid valve Z score ≥-3, presence of important tricuspid regurgitation, absence of coronary fistulae, and absence of subaortic stenosis are associated with a two-ventricle postnatal strategy.

Optimal Z-Score Use in Surgical Decision-Making in Pulmonary Atresia With Intact Ventricular Septum

Objectives:

In the surgical treatment of pulmonary atresia with intact ventricular septum, the size of the tricuspid valve annulus (as measured by z-scores) has emerged as a significant factor in deciding which repair to perform. Various tricuspid valve annulus z-scores are reported as “cutoffs” for successful biventricular repair. We aimed to determine whether the use of different z-score data sets contributed to the gross variation in “cutoffs” for successful biventricular repair reported in the literature.

Methods:

A single search was made of PubMed using the “advanced” setting with the following search terms: pulmonary, atresia, intact, septum, z, and score. The filters “title” and “title/abstract” were used for the first four and last two terms, respectively; the instruction “AND” combined all terms. Articles that identified which z-score data set was used in patients with biventricular repairs were included.

Results:

From 13 articles, 1,392 patients were studied, 410 (29.5%) of which achieved biventricular repair. Three z-score data sets were quoted; mean tricuspid valve annulus z-scores in biventricular repair patients ranged between −0.53 and −5.1. After correcting for discrepancies between z-score data sets, no study reported a mean tricuspid valve annulus z-score <−2.8 in biventricular repair patients and 83.3% reported mean tricuspid valve annuli z-scores >−1.7.

Conclusion:

The use of varied tricuspid valve annuli z-score data sets may have contributed to gross variations in reported “cutoffs” for successful biventricular repair. This could lead to inappropriate surgical pathway allocation.

Current Expectations for Cardiac Transplantation in Patients With Congenital Heart Disease

Congenital heart disease accounts for 40% of pediatric heart transplants and presents unique challenges to the transplant team. Suitability for transplantation is defined in part by degree of sensitization, pulmonary vascular resistance, and hepatic reserves. The incremental transplant risk for patients with congenital heart disease occurs within the first 3 months, after which survival is equivalent to transplantation for cardiomyopathy. Single ventricle with prior palliation, and especially the failing Fontan, carry the highest risk for transplantation and are least amenable to bridging with mechanical circulatory support. More effective bridging to transplant with mechanical circulatory support will require improvements in the adverse event profile of available pumps and the introduction of miniaturized continuous flow technology. The major barriers to routine long-term survival are chronic allograft failure and allograft vasculopathy. Despite these many challenges, continuing improvements in the care of pediatric heart transplant patients have pushed the median posttransplant survival past 15 years for children and to 20 years for infants.

Biventricular repair versus uni-ventricular repair for pulmonary atresia with intact ventrical septum: A systematic review

The management of pulmonary atresia with intact ventricular septum (PA/IVS) remains controversial. The goal of separating systematic and pulmonary circulation can be achieved by biventricular or uni-ventricular (Fontan or one and a half ventricle repair) strategies. Although outcomes have been improved, these surgical procedures are still associated with high mortality and morbidity. An optimal strategy for definitive repair has yet to be defined. We searched databases for genetically randomized controlled trials (RCTs) comparing biventricular with uni-ventricular repair for patient with PA/IVS. Data extraction and quality assessment were performed following the guidelines of the Cochrane Collaboration. Primary outcome measures were overall survival, and secondary criteria included exercise function, arrhythmia-free survival and treatment-related mortality. A total number of 669 primary citations were screened for relevant studies. Detailed analysis revealed that no RCTs were found to adequately address the research question and no systematic meta-analysis would have been carried out. Nevertheless, several retrospective analyses and case series addressed the question of finding right balance between biventricular and uni-ventricular repair for patient with PA/IVS. In this review, we will discuss the currently available data.

Decision-Making for Surgery in the Management of Patients with Univentricular Heart

A series of technical refinements over the past 30 years, in combination with advances in perioperative management, have resulted in dramatic improvements in the survival of patients with univentricular heart. While the goal of single-ventricle palliation remains unchanged - normalization of the pressure and volume loads on the systemic ventricle, the strategies to achieve that goal have become more diverse. Optimal palliation relies on a thorough understanding of the changing physiology over the first years of life and the risks and consequences of each palliative strategy. This review describes how to optimize surgical decision-making in univentricular patients based on a current understanding of anatomy, physiology, and surgical palliation.

Pulmonary atresia/intact ventricular septum: influence of coronary anatomy on single-ventricle outcome

BACKGROUND

We investigated the influence of coronary artery abnormalities on outcome in patients with pulmonary atresia/intact ventricular septum (PA-IVS) for planned single-ventricle palliation.

METHODS

Catheterization and medical records were reviewed in patients with PA-IVS for planned single-ventricle palliation at our institution between 2000 and 2012. Primary outcome was death or transplantation. Patients with confirmed or strong suspicion of stenosis in 2 or more main coronary arteries or coronary ostial atresia were defined as having right ventricle-dependent coronary circulation (RVDCC); those with stenosis of 1 main vessel or normal anatomy were defined as having non-RVDCC.

RESULTS

Of 58 patients with PA-IVS, 17 (30%) underwent single-ventricle palliation. Ten (59%) had RVDCC (3 with ostial atresia) and 7 (41%) had non-RVDCC. Median follow-up time was 8.2 years (0 months-11.3 years), with 1 patient in each group lost to follow-up. Five patients with RVDCC died, including the 3 patients with ostial atresia, and 1 underwent transplantation at 6 months of life. No deaths occurred after second-stage palliation. Three of the 4 surviving patients with RVDCC completed a Fontan operation, and 2 of these patients had evidence of cardiac ischemia on follow-up. No deaths occurred among patients with non-RVDCC. Kaplan-Meier analysis demonstrated significantly better survival in patients with non-RVDCC (100%) than in patients with RVDCC (40%) (p = 0.026).

CONCLUSIONS

In patients with PA-IVS undergoing single-ventricle palliation, RVDCC is associated with high early mortality, especially with coronary ostial atresia. There should be early consideration of transplantation in neonates with RVDCC. Patients with non-RVDCC undergoing single-ventricle palliation have excellent long-term outcomes, with no mortality seen in this series.

Pediatric heart transplantation-indications and outcomes in the current era

Pediatric heart transplantation (HTx) remains an important treatment option in the care of children with end-stage heart disease, whether it is secondary to cardiomyopathy or congenital heart disease (CHD). As surgical outcomes for CHD have improved, the indications for pediatric HTx have had to be dynamic, not only for children with CHD but also for the growing population of adults with CHD. As the field of pediatric HTx has evolved, the outcomes for children undergoing HTx have improved. This is undoubtedly due to the continued research efforts of both single-center studies, as well as research collaboratives such as the International Society for Heart and Lung Transplantation (ISHLT) and the Pediatric Heart Transplant Study (PHTS) group. Research collaboratives are increasingly important in pediatric HTx as single center studies for a limited patient population may not elicit strong enough evidence for practice evolution. Similarly, complications that limit the long term graft survival may occur in a minority of patients thus pooled experience is essential. This review focuses on the indications and outcomes for pediatric HTx, with a special emphasis on studies generated by these research collaboratives.

Pediatric heart transplantation-indications and outcomes in the current era

Pediatric heart transplantation (HTx) remains an important treatment option in the care of children with end-stage heart disease, whether it is secondary to cardiomyopathy or congenital heart disease (CHD). As surgical outcomes for CHD have improved, the indications for pediatric HTx have had to be dynamic, not only for children with CHD but also for the growing population of adults with CHD. As the field of pediatric HTx has evolved, the outcomes for children undergoing HTx have improved. This is undoubtedly due to the continued research efforts of both single-center studies, as well as research collaboratives such as the International Society for Heart and Lung Transplantation (ISHLT) and the Pediatric Heart Transplant Study (PHTS) group. Research collaboratives are increasingly important in pediatric HTx as single center studies for a limited patient population may not elicit strong enough evidence for practice evolution. Similarly, complications that limit the long term graft survival may occur in a minority of patients thus pooled experience is essential. This review focuses on the indications and outcomes for pediatric HTx, with a special emphasis on studies generated by these research collaboratives.

Fetal cardiac interventions: rationale, risk and benefit

Fetal congenital heart disease may progress during pregnancy and may lead to irreversible myocardial or pulmonary damage. The rationale of fetal intracardiac interventions is to change fetal hemodynamics, prevent secondary damage and improve long-term outcome at an acceptable risk for mother and fetus. This review focuses on the current experience about patient selection, risks and benefits of this technique.

Catheter-based treatment in patients with critical pulmonary stenosis or pulmonary atresia with intact ventricular septum: a single institute experience with comparison between patients with and without additional procedure for pulmonary flow

OBJECTIVES

We report a single institute experience of transcatheter pulmonary valvotomy using the soft end of a guidewire followed or not by a systemic-pulmonary shunt in patients with pulmonary atresia with intact ventricular septum (PAIVS) or critical pulmonary stenosis (CPS). In addition, we compare patients with or without an additional source of flow to support the pulmonary circulation after successful pulmonary valvotomy.

METHODS

All neonates with PAIVS or CPS who underwent primary transcatheter pulmonary valvotomy between January 2004 and December 2010 were reviewed retrospectively. Some of them needed an additional source of flow to support the pulmonary circulation. We performed a comparison between those who required an additional source of pulmonary flow and those who did not.

RESULTS

The initial procedure was successful in 20 out of 22 patients (seven of nine with PAIVS; all of 13 with CPS), but 10 of them needed an additional source of flow to support the pulmonary circulation: nine had arterial duct stenting and one had surgical Blalock-Taussig shunt. There were no deaths or major acute complications, except for femoral artery occlusion in three patients. The bipartite right ventricular morphology, the tricuspid z-score of ≤-0.74, the tricuspid to mitral valve ratio of ≤ 0.9, and the z-score of the diastolic interventricular septal thickness ≥ 2.37 in preprocedural examination showed more tendency of needing shunt placement.

CONCLUSION

Transcatheter pulmonary valvotomy using the soft end of a guidewire followed or not by the arterial duct stent implantation was an effective approach in those patients. The angiographic distinction between CPS and PAIVS did not affect anything in this study including the procedural method, success, and odds for reintervention. The degree of right ventricle cavity hypoplasia provided the main restriction to forward flow after pulmonary valvotomy.

Fetal intervention in right outflow tract obstructive disease: selection of candidates and results

Objectives. To describe the process of selection of candidates for fetal cardiac intervention (FCI) in fetuses diagnosed with pulmonary atresia-critical stenosis with intact ventricular septum (PA/CS-IVS) and report our own experience with FCI for such disease. Methods. We searched our database for cases of PA/CS-IVS prenatally diagnosed in 2003–2012. Data of 38 fetuses were retrieved and analyzed. FCI were offered to 6 patients (2 refused). In the remaining it was not offered due to the presence of either favourable prognostic echocardiographic markers (n = 20) or poor prognostic indicators (n = 12). Results. The outcome of fetuses with PA/CS-IVS was accurately predicted with multiparametric scoring systems. Pulmonary valvuloplasty was technically successful in all 4 fetuses. The growth of the fetal right heart and hemodynamic parameters showed a Gaussian-like behaviour with an improvement in the first weeks and slow worsening as pregnancy advanced, probably indicating a restenosis. Conclusions. The most likely type of circulation after birth may be predicted in the second trimester of pregnancy by means of combining cardiac dimensions and functional parameters. Fetal pulmonary valvuloplasty in midgestation is technically feasible and in well-selected cases may improve right heart growth, fetal hemodynamics, and postnatal outcome.

Changing trends in the management of pulmonary atresia with intact ventricular septum: the Melbourne experience

OBJECTIVE

Management of pulmonary atresia with intact ventricular septum (PAIVS) can be directed to either biventricular repair or univentricular palliation. The optimal management strategy has yet to be defined.

METHODS

All patients operated at the Royal Children's Hospital, Melbourne for PAIVS between 1990 and 2006 (n = 81) were reviewed. Patients were retrospectively stratified into a simple three-tiered classification based on right ventricle (RV) size. Multivariate logistic regression analysis was performed to identify risk factors of mortality.

RESULTS

The distribution of RV sizes was normal in 11 (14%), moderate hypoplasia in 45 (56%), and severe hypoplasia in 25 (31%) patients. RV-to-coronary-artery connections were present in 33 (41%) and RV coronary dependence in six patients (7%). Sixteen patients died (20%). The end-status of the remaining patients was biventricular repair in 31/81 (38%), 1½-ventricle repair in 10/81 (12%), Fontan circulation in 14/81 (17%), transplantation in 1/81 (1%), and still awaiting repair in 9/81 (11%). Ten-year survival was 80% (95% confidence interval (CI): 71-87%). Independent predictors of mortality were lower tricuspid valve (TV) annulus size Z-score and the presence of RV-to-coronary-artery connections.

CONCLUSIONS

A simple three-tiered classification based on RV size may allow initial stratification into biventricular or univentricular repair for patients with normal RV size and severe RV hypoplasia. In patients with moderate RV hypoplasia, the presence of RV-to-coronary-artery connections or a TV Z-score<-2 should caution one against attempting biventricular repair.

Paroxysmal complete atrioventricular block in a patient with pulmonary atresia and intact ventricular septum

Sudden death in pulmonary atresia and intact ventricular septum with right ventricular dependent coronary circulation is a well-established complication, and is thought to be caused by myocardial ischaemia. We report a case of paroxysmal complete atrioventricular block that raises the possibility of an additional mechanism of sudden death.

Modified Blalock–Taussig Shunt: Immediate and Short-Term Follow-Up Results in Neonates

INTRODUCTION

The modified Blalock-Taussig shunt (MBTS) is the most commonly created systemic-pulmonary shunt in neonates with cyanotic heart disease. Morbidity and mortality after MBTS is associated with several factors including age, pulmonary artery diameter and the baseline cardiac anatomy. The objective of this research was to describe the immediate and short-term follow-up results of MBTS in Pakistani neonates.

METHODS AND RESULTS

A retrospective review of patient charts was done to select 22 neonatal cases of various types of cyanotic heart diseases who had undergone MBTS creation from 1999 to 2005. Clinical and echocardiographic data were collected. Patients were followed up on their post-operative visits. Twenty-two neonates, 14 males and 8 females, mean age 11.2+/-6.9, underwent MBTS surgery during the six-year period of study. Pulmonary artery diameters were 3+/-0.2 and 2.9+/-0.2 for the right and left arteries, respectively. All patients received a 4mm Gor-Tex shunt through a postero-lateral thoracotomy approach. The mean duration of post-operative mechanical ventilation was 3.9+/-4.5 days. Three neonates (13.6%) died within one month of surgery while another three (13.6%) died after three months of surgery. Among these deaths, two were due to shunt occlusion/failure (9%) and the rest were due to non-cardiac causes. Another two patients underwent revision of surgery after shunt failure. Pulmonary atresia with intact interventricular septum was the most common cardiac anomaly in our series.

CONCLUSIONS

The mortality rate in neonates is highest during the first post-operative month. Shunt thrombosis and occlusion can be sudden and fatal therefore coagulation profile should be carefully monitored especially in the peri-operative period. PA-IVS was the most common anatomical variant in our limited experience and had high morbidity and mortality rate after surgery.

The prevalence of coronary arterial abnormalities in pulmonary atresia with intact ventricular septum and their influence on surgical results

BACKGROUND

The relatively high mortality in patients with pulmonary atresia and intact ventricular septum may be related to the presence of significant coronary arterial anomalies. This retrospective review of cineangiocardiograms was undertaken to further elucidate the types and variety of such coronary arterial abnormalities, and to assess their effect on postoperative survival.

MATERIAL AND RESULTS

Details regarding coronary arterial anatomy and abnormalities were assessed in 116 patients. We noted the site and severity of lesions, and the presence of fistulous communications from the right ventricle to the coronary arteries, assessing the proportion of left ventricular myocardium affected by coronary arterial interruptions or significant stenoses, in other words, the amount dependent on coronary circulation from the right ventricle. We also measured diameters of the tricuspid and mitral valves. Fistulas were found in 87 patients (75%), interruptions of major coronary arteries in 40 patients (34%), lack of connections between the coronary arteries and the aorta in 18 patients (16%), and single origin of a coronary artery, with the right coronary artery arising from the left, in 6 patients (5%). We found increased mortality in 47 patients (40%) who had a right ventricular-dependent coronary arterial circulation. The presence of fistulas in itself was not associated with higher mortality, but the presence of coronary arterial interruptions (p = 0.05), and a higher myocardial score (p = 0.0009), were.

CONCLUSION

We encountered a higher prevalence of both coronary arterial abnormalities and right ventricular-dependent circulation than previously reported. Awareness of the severity of the coronary arterial abnormalities should assist in planning treatment.

Pulmonary Atresia With Intact Ventricular Septum: Limitations of Catheter-Based Intervention

BACKGROUND

Pulmonary atresia with intact ventricular septum (PAIVS) has a wide spectrum of anatomic heterogeneity and invokes a wide variety of treatment strategies. We reviewed the outcome of our patients with PAIVS in order to delineate strategies for the optimal management of PAIVS. In particular, the possibility of avoiding neonatal surgical intervention with catheter-based technology was assessed.

METHODS

The study cohort was composed of all patients presented with PAIVS from January 1999 through December 2005. Demographic and anatomic variables were analyzed to determine association with in-hospital mortality.

RESULTS

Forty-four infants with PAIVS underwent catheter valvuloplasty (n = 17) and (or) surgical intervention (n = 42). The mean age and weight of the infants was six days and 3.1 kg, and the average follow-up was 40 +/- 29.5 months. Five (11%) had right ventricle dependent coronary circulation (RVDCC) and six (14%) had Ebstein's anomaly. Five (11%) patients died. Of those who underwent catheter valvotomy, three (18%) underwent shunt placement, 12 (71%) underwent right ventricular outflow tract reconstruction with shunt placement, and only two (12%) did not require a further surgical intervention in the newborn period. Multivariable analyses demonstrated RVDCC (odds ratio 21.3, p = 0.025) and Ebstein's anomaly (odds ratio 16.0, p = 0.038) to be risk factors for in-hospital mortality. Of those patients with Ebstein's anomaly, a single ventricle approach had a better outcome.

CONCLUSIONS

We demonstrated excellent recent outcomes for patients with PAIVS. Catheter-based interventions rarely avoid surgical repair. The RVDCC and Ebstein's anomaly were associated with high mortality. In patients with Ebstein's anomaly, single ventricular pathway may be the better strategy for this specific patient population.

Indications for Heart Transplantation in Pediatric Heart Disease

Background— Since the initial utilization of heart transplantation as therapy for end-stage pediatric heart disease, improvements have occurred in outcomes with heart transplantation and surgical therapies for congenital heart disease along with the application of medical therapies to pediatric heart failure that have improved outcomes in adults. These events justify a reevaluation of the indications for heart transplantation in congenital heart disease and other causes of pediatric heart failure.

Methods and Results— A working group was commissioned to review accumulated experience with pediatric heart transplantation and its use in patients with unrepaired and/or previously repaired or palliated congenital heart disease (children and adults), in patients with pediatric cardiomyopathies, and in pediatric patients with prior heart transplantation. Evidence-based guidelines for the indications for heart transplantation or retransplantation for these conditions were developed.

Conclusions— This evaluation has led to the development and refinement of indications for heart transplantation for patients with congenital heart disease and pediatric cardiomyopathies in addition to indications for pediatric heart retransplantation.

Echocardiographic predictors of outcome in fetuses with pulmonary atresia with intact ventricular septum

OBJECTIVE

We sought to identify in utero predictors of postnatal outcomes in fetal patients with pulmonary atresia with intact ventricular septum (PAIVS) or critical pulmonary stenosis.

BACKGROUND

Although PAIVS or critical pulmonary stenosis can be diagnosed in utero by echocardiography, our ability to predict outcomes is limited.

METHODS

Fetal echocardiograms from 28 patients with PAIVS/critical pulmonary stenosis were retrospectively reviewed. Tricuspid valve (TV) annulus, right and left ventricular internal dimensions, and degree of tricuspid regurgitation were recorded. To establish normal fetal values, echocardiograms from healthy patients were analyzed in an identical fashion.

RESULTS

Both a fetal TV z score of -4 or less beyond 23 weeks of gestation and a fetal TV annulus of 5 mm or less beyond 30 weeks of gestation were predictive of poor postnatal outcomes. In addition, right:left ventricular length or width less than 0.5 and/or the absence of tricuspid regurgitation were predictive of poor outcome.

CONCLUSIONS

TV annulus size, right:left ventricular ratios, and presence of tricuspid regurgitation on fetal echocardiograms may aid in guiding prenatal counseling regarding postnatal outcome in PAIVS.

Management algorithm in pulmonary atresia with intact ventricular septum

Pulmonary atresia with intact ventricular septum (PAIVS) is a disease with remarkable morphologic variability, affecting not only the pulmonary valve but also the tricuspid valve, the RV cavity and coronary arteries. With advances in interventional techniques and congenital heart surgery, the management of PAIVS continues to evolve. This review is an attempt at providing a practical approach to the management of this disease. The basis of our approach is morphologic classification as derived from echocardiography and angiography. Group A, patients with good sized RV and membranous atresia, the primary procedure at presentation is radiofrequency (RF) valvotomy. Often it is the only procedure required in this group with the most favourable outcome. Patients with severely hypoplastic RV (Group C) are managed along the lines of hearts with single ventricle physiology. The treatment at presentation is patent ductus arteriosus (PDA) stenting with balloon atrial septostomy or conventional modified Blalock Taussig (BT) shunt. Bidirectional Glenn shunt may be done 6-12 months later followed by Fontan completion after a suitable interval. Patients in Group B, the intermediate group, are those with borderline RV size, usually with attenuated trabecular component but well developed infundibulum. The treatment at presentation is RF valvotomy and PDA stenting +/- balloon atrial septostomy. Surgical re-interventions are not uncommonly required viz. bidirectional Glenn shunt when the RV fails to grow adequately (11/2 - ventricle repair) and right ventricular outflow tract (RVOT) reconstruction for subvalvar obstruction or small pulmonary annulus. Catheter based interventions viz. repeat balloon dilatation or device closure of patent foramen ovale (PFO) may also be required in some patients.

Fetal tricuspid valve size and growth as predictors of outcome in pulmonary atresia with intact ventricular septum

OBJECTIVE

Pulmonary atresia with intact ventricular septum is a complex congenital cardiovascular anomaly that frequently requires single ventricle palliation. Fetal diagnosis of pulmonary atresia with intact ventricular septum is common, but the natural history of pulmonary atresia with intact ventricular septum diagnosed in midgestation, predictors of neonatal anatomy, and predictors of biventricular repair have not been determined. The objective of this study was to determine whether the size and rate of growth of the fetal tricuspid valve predict neonatal anatomy and biventricular repair.

DESIGN AND RESULTS

Twenty-three fetuses diagnosed with pulmonary atresia with intact ventricular septum between 1990 and 2004 were studied. Of 13 fetuses with a midgestation fetal tricuspid valve z score < or = -3, 1 achieved biventricular repair, compared with 5 of 5 with a tricuspid valve z score > -3. Of 13 fetuses with a midgestation fetal tricuspid valve z score < or = -3, 8 were diagnosed postnatally with a right ventricular dependent coronary circulation, compared with none with a tricuspid valve z score > -3. Midgestation and late gestation fetal tricuspid valve z scores correlated with neonatal tricuspid valve z score. The average rate of tricuspid valve growth between mid- and late fetal echocardiograms was significantly lower in patients who did not achieve biventricular repair than in those who did (0.012 +/- 0.008 cm per week vs 0.028 +/- 0.014 cm per week).

CONCLUSIONS

Fetal tricuspid valve z score and rate of growth predict postnatal outcome in pulmonary atresia with intact ventricular septum. These findings may have important implications for prenatal counseling and selection of patients for fetal pulmonary valve dilation.

Fertility, pregnancy, and delivery after biventricular repair for pulmonary atresia with an intact ventricular septum

The objective of the present study to investigate fertility, pregnancy, and delivery in women with biventricular repair for pulmonary atresia with an intact ventricular septum (PAIVS). Using a nationwide registry (CONCOR), 37 patients with pulmonary atresia were identified, 6 of whom (aged 21 to 34 years) had biventricular repair for PAIVS. Three PAIVS patients had a total of 5 pregnancies, including 1 abortion and 1 ectopic pregnancy. Besides minor noncardiac complications, the 3 live-birth pregnancies were successful. None of the women reported infertility or irregularities (hypermenorrhea, dysmenorrhea, polymenorrhoea, oligomenorrhea, or amenorrhea) of their natural menstrual cycle. In conclusion, successful pregnancy in women with biventricular repair for PAIVS is possible, and only minor complications were observed. Infertility and menstrual cycle disorders do not appear to be more prevalent than usual.

Natural History of Pulmonary Atresia With Intact Ventricular Septum and Right-Ventricle–Dependent Coronary Circulation Managed by the Single-Ventricle Approach

BACKGROUND

Long-term outcome of patients with pulmonary valvar atresia and intact ventricular septum with right-ventricle-dependent coronary circulation (PA/IVS-RVDCC) managed by staged palliation directed toward Fontan circulation is unknown, but should serve as a basis for comparison with management protocols that include initial systemic-to-pulmonary artery shunting followed by listing for cardiac transplantation.

METHODS

Retrospective review of patients admitted to our institution with the diagnosis of PA/IVS-RVDCC from 1989 to 2004. All angiographic imaging studies, operative reports, and follow-up information were reviewed. Right-ventricle-dependent coronary circulation was defined as situations in which ventriculocoronary fistulae with proximal coronary stenosis or atresia were present, putting significant left ventricle myocardium at risk for ischemia with right ventricle decompression.

RESULTS

Thirty-two patients were identified with PA/IVS-RVDCC. All underwent initial palliation with modified Blalock-Taussig shunt (BTS). Median tricuspid valve z-score was -3.62 (-2.42 to -5.15), and all had moderate (n = 13) or severe (n = 19) right ventricular hypoplasia. Median follow-up was 5.1 years (9 months to 14.8 years). Overall mortality was 18.8% (6 of 32), with all deaths occurring within 3 months of BTS. Aortocoronary atresia was associated with 100% mortality (3 of 3). Of the survivors (n = 26), 19 have undergone Fontan operation whereas 7, having undergone bidirectional Glenn shunt, currently await Fontan. Actuarial survival by the Kaplan-Meier method for all patients was 81.3% at 5, 10, and 15 years, whereas mean survival was 12.1 years (95% confidence interval: 10.04 to 14.05). No late mortality occurred among those surviving beyond 3 months of age.

CONCLUSIONS

In patients with PA/IVS-RVDCC, early mortality appears related to coronary ischemia at the time of BTS. Single-ventricle palliation yields excellent long-term survival and should be the preferred management strategy for these patients. Those with aortocoronary atresia have a particularly poor prognosis and should undergo cardiac transplantation.

Successful Management of Patients With Pulmonary Atresia With Intact Ventricular Septum Using a Three Tier Grading System for Right Ventricular Hypoplasia

BACKGROUND

We sought to validate a simple grading scheme for right ventricular hypoplasia in determining suitability for a biventricular repair.

METHODS

We reviewed the medical records for 106 patients with pulmonary atresia-intact ventricular septum (PA-IVS) treated between 1982 and 2001. Over this period, children were assigned to mild (> 2/3 normal size, 23.7% of patients), moderate (1/3 to 2/3, 41.2%), or severe (1/3, 35.1%) right ventricular hypoplasia, and this grouping, along with severity of coronary anomalies (45% right ventricle to coronary fistulae, 16% with right ventricle dependent coronary circulation [RVDCC]), triaged children to eventual single ventricle (severe) or two-ventricle (mild or moderate) repair.

RESULTS

Actuarial 10-year survival was 86.3% with mortality predicted by severe hypoplasia (odds ratio [OR] 12.9, p < 0.001), RVDCC (OR 15.0, p < 0.001), and non-Caucasian race (OR 10.7, p < 0.001). Multivariate analysis with a Cox proportional hazards model confirmed only RVDCC (risk ratio [RR] 10.9, p = 0.0009} and non-Caucasian race (RR 6.9, p = 0.007) as significant. Although not an independent risk factor for survival, the degree of hypoplasia was the most important determinant for definitive repair. Severe hypoplasia virtually precluded two-ventricle repair (OR 33.1, p < 0.001 by chi2 analysis) and was the strongest risk factor for a one-ventricle system (OR 78.7, p < 0.001). Actuarial survival after either repair was 91%, and no biventricular repair later converted to a Fontan system.

CONCLUSIONS

Surgical management of patients based on this three tier grade for right ventricular hypoplasia results in excellent survival and correctly predicts patients destined for eventual Fontan and biventricular repair.

Does a bidirectional Glenn shunt improve the oxygenation of right ventricle–dependent coronary circulation in pulmonary atresia with intact ventricular septum?

OBJECTIVE

There is a risk of myocardial ischemia in patients with pulmonary atresia and intact ventricular septum associated with the right ventricle-dependent coronary circulation. In this patient group, the oxygen delivery to the myocardium depends on the oxygen saturation of the right ventricular cavity. We hypothesized that bidirectional Glenn shunt would improve the oxygenation of right ventricle-dependent coronary circulation relative to a systemic-pulmonary artery shunt. The reduction of systemic venous return to the right atrium due to a bidirectional Glenn shunt could increase the oxygen saturation of the right ventricle in the clinical setting, when the mixture of systemic and pulmonary venous blood is unchanged at the atrial level.

METHODS

Patients with right ventricle-dependent coronary circulation were defined as those with right ventricle-coronary artery fistulas plus stenoses of the right or left coronary arteries. For 7 patients with right ventricle-dependent coronary circulation before and after bidirectional Glenn shunt, cardiac catheterization was performed and the oxygen saturation of the right ventricular cavity was measured.

RESULTS

For all 7 patients, the bidirectional Glenn shunt was performed at a mean age of 18 months. Ischemic changes in the electrocardiogram before the bidirectional Glenn shunt improved after the procedure in 2 patients. The oxygen saturation of the right ventricular cavity before the bidirectional Glenn shunt was 54.6 +/- 8.8%, and that after the BGS significantly increased to 75.6% +/- 5.8% (P < .01). All 7 patients have subsequently undergone the Fontan procedure with excellent results.

CONCLUSION

Early bidirectional Glenn shunt could prevent progression of myocardial ischemia in pulmonary atresia with intact ventricular septum with right ventricle-dependent coronary circulation.

Pulmonary atresia with intact ventricular septum: Predictors of early and medium-term outcome in a population-based study

OBJECTIVES

Pulmonary atresia with intact ventricular septum is a form of congenital heart disease usually associated with right-heart hypoplasia, with considerable morphologic heterogeneity and often poor outlook. Ascertainment of risk factors for poor outcome is an important step if an improvement in outcome is to be achieved.

METHODS

The UK and Ireland Collaborative study of Pulmonary Atresia with Intact Ventricular Septum is an ongoing population-based study of all patients born with this disease from 1991 through 1995. All available clinical, morphologic, and investigative variables were directly reviewed, and risk factor analysis was performed for poor outcome.

RESULTS

One hundred eighty-three patients presented with pulmonary atresia with intact ventricular septum. Fifteen underwent no procedure, and all died. Of the remainder, 67 underwent a right ventricular outflow tract procedure (catheter or surgical), 18 underwent an outflow tract procedure with shunt, and 81 underwent a systemic-to-pulmonary shunt alone. One- and 5-year survival was 70.8% and 63.8%, respectively. Results from Cox proportional hazards model analysis showed that low birth weight (P = .024), unipartite right ventricular morphology (P = .001), and the presence of a dilated right ventricle (P < .001) were independent risk factors for death. The presence of coronary artery fistulae, right ventricular dependence, or the tricuspid valvar z score did not prove to be risk factors for death. After up to 9 years of follow-up, 29% have achieved a biventricular repair, 3% a so-called one-and-a-half ventricular repair, and 10.5% a univentricular repair, with 16.5% still having a mixed circulation (41% died).

CONCLUSIONS

This population-based study has shown which features at presentation place an infant in a high-risk group. This is important information for counseling in fetal life and for surgical strategy after birth.