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

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

Pulmonary Atresia with Intact Ventricular Septum: Midterm Outcomes from a Multicenter Cohort

Contemporary multicenter data regarding midterm outcomes for neonates with pulmonary atresia with intact ventricular septum are lacking. We sought to describe outcomes in a contemporary multicenter cohort, determine factors associated with end-states, and evaluate the effect of right ventricular coronary dependency and coronary atresia on transplant-free survival. Neonates treated during 2009-2019 in 19 United States centers were reviewed. Competing risks analysis was performed to determine cumulative risk of each end-state, and multivariable regression analyses were performed to identify factors associated with each end-state and transplant-free survival. We reviewed 295 patients. Median tricuspid valve Z-score was - 3.06 (25%, 75%: - 4.00, - 1.52). Final end-state was biventricular repair for 45 patients (15.2%), one-and-a half ventricle for 16 (5.4%), Fontan for 75 (25.4%), cardiac transplantation for 29 (9.8%), and death for 54 (18.3%). Seventy-six patients (25.7%) remained in mixed circulation. Cumulative risk estimate of death was 10.9%, 16.1%, 16.9%, and 18.8% at 1, 6 months, 1 year, and 5 years, respectively. Tricuspid valve Z-score was inversely, and coronary atresia positively associated with death or transplantation [odds ratio (OR) = 0.46, (95% confidence interval (CI) = 0.29-0.75, p < 0.001) and OR = 3.75 (95% CI 1.46-9.61, p = 0.011), respectively]. Right ventricular coronary dependency and left coronary atresia had a significant effect on transplant-free survival (log-rank p < 0.001). In a contemporary multicenter cohort of patients with PAIVS, consisting predominantly of patients with moderate-to-severe right ventricular hypoplasia, we observed favorable survival outcomes. Right ventricular coronary dependency and left, but not right, coronary atresia significantly worsens transplant-free survival.

Procedural Sedation in Congenital Heart Disease

Procedural sedation in patients with congenital heart disease (CHD) is associated with significant morbidity and mortality. It is vital for the practitioner to fully understand the complexity of lesions, their hemodynamics, and the impact of medications commonly used for procedural sedation on the stability of systemic vascular resistance and pulmonary flow. According to the literature, we explain the interaction of the systemic vascular resistance and pulmonary flow in such lesions and divide them into five categories outlined in this article: (1) CHDs with left-to-right shunt with normal pulmonary arterial pressure and resistance, (2) CHD with left-to-right shunt and moderate to severe elevation of pulmonary arterial pressure with near-normal pulmonary vascular resistance, (3) CHD with pulmonary flow dependent on systemic vascular resistance, (4) patients with congenital coronary stenosis and coronary anomalies, and 5) aortic obstructive lesions.

The Utility of CT Angiography in Neonates with Pulmonary Atresia with Intact Ventricular Septum and Concern for Right Ventricular Dependent Coronary Circulation: Case Series

Up to one third of patients with pulmonary atresia with intact ventricular septum (PA-IVS) will have inadequate anterograde coronary blood flow and rely on fistulous connections from the right ventricle (RV) for myocardial perfusion, known as RV-dependent coronary circulation (RVDCC). Historically, identification of the extent of ventriculocoronary connections and coronary stenosis has required invasive imaging with cardiac catheterization and angiography. Cardiac computed tomography (CCT) potentially provides a less invasive imaging option for therapeutic planning in this group of patients. We describe six neonates with PA-IVS who underwent both CCT and cardiac catheterization at our institution prior to any surgical or transcatheter intervention between 2009 and 2019. Imaging was concerning for RVDCC in all six patients. The average tricuspid Z-score was - 4.19 (2.1 to - 5.34). Two patients underwent cardiac transplantation and two patients underwent ductal stenting. The overall mortality rate was 50%. CCT findings closely mirrored the findings of invasive cardiac catheterization and identified important morphological variations. The average radiation exposure (DLP) per CCT was (10.5 mGy cm, range 6-20). Technological improvements in CCT have enabled adequate visualization of coronary anomalies in children with comparable accuracy to cardiac catheterization, but considerably less radiation exposure. However, diagnosis of RVDCC requires direct right ventricular angiography. Therefore, the potential benefit of obtaining a CCT prior to catheterization for infants with PA-IVS is the ability to risk stratify, assist with procedural planning, and improve family counseling.

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.

Right ventricular outflow tract anomalies: Neonatal interventions and outcomes

Right ventricular outflow tract (RVOT) anomalies comprise a wide spectrum of congenital heart disease, typically characterized by obstruction to flow from the right ventricle to pulmonary arteries. This review highlights important considerations surrounding management strategy as well as clinical outcomes for the neonate with RVOT anomaly, including: pulmonary atresia with intact ventricular septum, congenital pulmonary valve stenosis, tetralogy of Fallot, and Ebstein anomaly with anatomic or physiologic RVOT obstruction.

Very preterm and very low birthweight infant with pulmonary atresia intact ventricular septum, right ventricle-dependent coronary circulation, and discontinuous pulmonary arteries

Prematurity and low birthweight are associated with increased mortality in infants undergoing cardiac surgery. Pulmonary atresia with intact ventricular septum and right ventricle-dependent coronary circulation carries one of the highest risks of mortality. We present a patient who was born at 28 weeks of gestation at 1.2 kg, with pulmonary atresia intact ventricular septum, right ventricle-dependent coronary circulation, coronary artery atresia, and discontinuous pulmonary arteries, who successfully underwent palliation with a modified Blalock-Taussig shunt, pulmonary arterioplasty, and subsequently a bidirectional Glenn.

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.

Predictors of death after receiving a modified Blalock-Taussig shunt in cyanotic heart children: A competing risk analysis

Objective

To determine risk factors affecting time-to-death ≤90 and >90 days in children who underwent a modified Blalock-Taussig shunt (MBTS).

Methods

Data from a retrospective cohort study were obtained from children aged 0–3 years who experienced MBTS between 2005 and 2016. Time-to-death (prior to Glenn/repair), time-to-alive up until December 2017 without repair, and time-to-progression to Glenn/repair following MBTS were presented using competing risks survival analysis. Demographic, surgical and anesthesia-related factors were recorded. Time-to-death ≤90 days and >90 days was analyzed using multivariate time-dependent Cox regression models to identify independent predictors and presented by adjusted hazard ratios (HR) and 95% confidence intervals (CI).

Results

Of 380 children, 119 died, 122 survived and 139 progressed to Glenn/repair. Time-to-death probability (95% CI) within 90 days was 0.18 (0.14–0.22). Predictors of time-to-death ≤90 days (n = 63) were low weight (<3 kg) (HR 7.6, 95% CI:2.8–20.4), preoperative ventilator support (HR 2.7, 95% CI:1.3–5.6), postoperative shunt thrombosis (HR 5.0, 95% CI:2.4–10.4), bleeding (HR 4.5, 95% CI:2.1–9.4) and renal failure (HR 4.1, 95% CI:1.5–10.9). Predictors of time-to-death >90 days (n = 56) were children diagnosed with pulmonary atresia with ventricular septal defect and single ventricle (compared to tetralogy of fallot) (HR 3.2, 95% CI:1.2–7.7 and HR 3.1, 95% CI:1.3–7.6, respectively), shunt size/weight ratio >1.1 vs <0.65 (HR 6.8, 95% CI:1.4–32.6) and longer duration of mechanical ventilator (HR 1.002, 95% CI:1.001–1.004). Shunt size/weight ratio ≥1.0 (vs <1.0) and ≥0.65 (vs <0.65) were predictors for overall time-to-death in neonates and toddlers, respectively (HR 13.1, 95% CI:2.8–61.4 and HR 7.8, 95% CI:1.7–34.8, respectively).

Conclusions

Perioperative factors were associated with time-to-death ≤90 days, whereas particular cardiac defect, larger shunt size/weight ratio, and longer mechanical ventilation were associated with time-to-death >90 days after receiving MBTS. Larger shunt size/weight ratio should be reevaluated within 90 days to minimize the risk of shunt over flow.

A low threshold for neonatal intervention yields a high rate of biventricular outcomes in pulmonary atresia with intact ventricular septum

AIMS

Management strategies for pulmonary atresia with intact ventricular septum are variable and are based on right ventricular morphology and associated abnormalities. Catheter perforation of the pulmonary valve provides an alternative strategy to surgery in the neonatal period. We sought to assess the long-term outcome in terms of survival, re-intervention, and functional ventricular outcome in the setting of a 26-year single-centre experience of low threshold inclusion criteria for percutaneous valvotomy.

METHODS AND RESULTS

Retrospective analysis of patients diagnosed with pulmonary atresia with intact ventricular septum from 1990 to 2016 at a tertiary referral centre, was performed. Of 71 patients, 48 were brought to the catheterisation laboratory for intervention. Catheter valvotomy was successful in 45 patients (94%). Twenty-three patients (51%) also underwent ductus arteriosus stenting. The length of intensive care and hospital stay was significantly shorter, and early re-interventions were significantly reduced in the catheterisation group. There were eight deaths (17%); all within 35 days of the procedure. Of the survivors, only one has required a Fontan circulation. Twenty-eight patients (74%) have undergone biventricular repair and nine patients (24%) have one-and-a-half ventricle circulation. Following successful valvotomy, 80% of patients required further catheter-based or surgical interventions.

CONCLUSIONS

A low threshold for initial interventional management yielded a high rate of successful biventricular circulations. Although mortality was low in patients who survived the peri-procedural period, the rate of re-intervention remained high in all groups.

Low prenatal detection rate of valvar pulmonary stenosis: What are we missing?

OBJECTIVES

Critical pulmonary stenosis (PS) and pulmonary atresia with intact ventricular septum (PAIVS) require urgent neonatal intervention. Since PS may be more insidious than PAIVS during gestation, we hypothesized that neonates with PS would have lower rates of prenatal detection than PAIVS.

METHODS

We performed a retrospective chart review of all neonates who underwent diagnostic or interventional cardiac catheterization between 2000 and 2014 for critical PS or PAIVS. The rates of prenatal diagnosis were calculated for PS and PAIVS. Prenatal and postnatal echocardiographic data were reviewed.

RESULTS

178 patients met inclusion criteria: 91 with critical PS and 87 with PAIVS. The prenatal diagnosis rate for critical PS was lower than for PAIVS at 37% (34/91) vs 60% (52/87) (P = .003). At the time of diagnosis at a median gestational age of 25 weeks, the median TV z-score for patients with critical PS was larger than in PAIVS (-0.15 vs -3.0 P = .004).

CONCLUSION

Critical PS had a lower prenatal detection rate than PAIVS, likely due to a relatively normal 4-chamber view at the time of routine second trimester screening in patients with PS. Color flow Doppler of the outflow tracts may improve detection, since outflow tracts may appear normal by 2D imaging.

Neonatal Pulmonary Atresia With Intact Ventricular Septum-8-Year Surgical Experience at One Center

BACKGROUND

Surgical treatment of pulmonary atresia with intact ventricular septum (PA/IVS) in neonates is challenging because of the broad variations of right ventricular (RV) malformations. In this retrospective study, we summarized our 8-y experience in surgical management for neonatal PA/IVS patients.

METHODS

Thirty-four neonates with PA/IVS between July 1, 2006 and June 30, 2014, were reviewed. Patients were categorized into three groups: mild, moderate, and severe RV hypoplasia according to RV morphology and development. Patients were on regular follow-up for at least 5 y. Overall survival, complications, reinterventions, risk factors for mortality, and health status were evaluated.

RESULTS

21 patients (61.8%) were treated with biventricular repair, eight patients (23.5%) with Fontan procedure, and one patient (2.9%) with bidirectional Glenn procedure. There were four postprocedural mortalities and one late death. The 5-y survival rates after final surgical repair for mild, moderate, and severe RV hypoplasia groups were 100%, 100%, and 88.9%, respectively. The reintervention rates were 0% (0/4), 21.4% (3/14), and 55.6% (5/9) for the subgroups, respectively. At the latest follow-up, most patients had a status characterized as New York Heart Association class I (88.9%, 24/27).

CONCLUSIONS

Surgical management for PA/IVS in neonates should be individualized. Favorable early and long-term outcomes can be achieved in neonatal PA/IVS patients by individualized surgical strategies, regardless of the degree of RV hypoplasia. In spite of potential RV catch-up development, the degree of RV hypoplasia is a factor of paramount importance to assess PA/IVS in neonates.

Pulmonary Atresia With Ventriculocoronary Arterial Connections and a Large Conoventricular Septal Defect

Ventriculocoronary arterial connections are typically found in patients with pulmonary atresia with an intact ventricular septum. This report describes a case of ventriculocoronary arterial connections in a patient with pulmonary atresia with a ventricular septal defect. Our case supports recent data suggesting a primary coronary artery developmental anomaly in pulmonary atresia. (Level of Difficulty: Advanced.)

Prenatal echocardiographic classification and prognostic evaluation strategy in fetal pulmonary atresia with intact ventricular septum

Fetal pulmonary atresia with intact ventricular septum (PA/IVS) is a rare congenital heart disease. The present study aimed to classify PA/IVS and determine the relationship between prenatal echocardiographic characteristics and postnatal biventricular or univentricular repair strategies.A total of 51 fetuses with PA/IVS were examined from 2012 to 2019. Data on prenatal echocardiography, associated anomaly, karyotype, and outcome were collected. Two-dimensional measurements included tricuspid valve (TV) z-score, mitral valve (MV) z-score, TV/MV ratio, and ratio of right to left ventricle (RV/LV) length, whereas color Doppler measurements included degree of tricuspid regurgitation (TR), ventriculo-coronary artery communication (VCAC), tricuspid inflow duration (TID), cardiac cycle duration (CCD), middle cerebral artery pulsatility index (MCA PI), and umbilical artery pulsatility index (UA PI). Diagnostic classification was based on the development of RV and the presence or absence of VCAC. Postnatal evaluation was divided according biventricular or univentricular repair.Of the 51 fetuses with PA/IVS, 20 were type I, 17 were type II, and 14 were type III. Only one fetus exhibited right aortic arch. The karyotype of all the fetuses was normal. Of the 28 patients who underwent postnatal surgery, 13 (46%) underwent biventricular repair and 15 (54%) underwent univentricular repair. TV z-score was significantly higher for the biventricular repair group compared with univentricular repair group (-1.20 ± 0.98 vs -4.33 ± 0.80, P = .000). TV/MV, RV/LV length, and TID/CCD were significantly higher for the biventricular repair group than the univentricular repair group (0.81 ± 0.14 vs 0.54 ± 0.09, 0.71 ± 0.11 vs 0.49 ± 0.09, 39.20 ± 3.84 vs 29.16 ± 4.58, P = .000). Moderate or severe TR and VCAC were significantly different between the 2 groups (P = .000). Gestational age, MCA PI, and UA PI did not differ between the 2 groups (P = .72, P = .36, P = .06). The cutoff values for the biventricular repair characteristic curves were TV z-score >-3.28, TV/MV ratio >0.71, RV/LV length >0.62, and TID/CCD >33.95%. The sensitivities of the TV z-score, TV/MV, RV/LV length, and TID/CCD were 100%, 77%, 85%, and 92%, respectively. The specificities of the TV z-score, TV/MV, RV/LV length, and TID/CCD were 94%, 100%, 100%, and 94%, respectively.Fetal echocardiography was able to classify PA/IVS according to variable degree of RV and VCAC. In fetal PA/IVS, TV z-score >-3.28, TV/MV >0.71, RV/LV length >0.62, TID/CCD >33.95%, moderate and severe TR, and the absence of VCAC were associated with postnatal biventricular repair strategy. These findings may have implications for prenatal counseling and prediction of fetal outcome.

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.

[Percutaneous management of pulmonary atresia with intact ventricular septum and critical pulmonary stenosis]

INTRODUCTION

Pulmonary atresia with intact ventricular septum and critical pulmonary stenosis in newborns encompasses a wide spectrum of disease, including cases with significant right ventricular hypoplasia and coronary artery to right ventricle fistulae, which may be considered a contraindication for decompression of the right ventricle. The aim of this study was to review the middle- and long-term outcomes of these patients over 20 years and identify differential factors between both groups, including patients with coronary artery fistulae.

PATIENTS AND METHODS

We performed a descriptive retrospective study by identifying all patients that received a diagnosis of pulmonary atresia with intact ventricular septum and critical pulmonary stenosis between January 1996 and January 2018. We collected and analysed data regarding right ventricular morphology, surgical management, percutaneous intervention and medium- and long-term outcomes.

RESULTS

51 patients were admitted. A total of 9 patients (17.6%) died during the followup. None of the deceased patients had coronary artery to right ventricle fistulae. The median length of follow up in the 42 survivors was 8.9 years (1-16). The functional class based on the latest revision of the New York Heart Association classification was 1.2 for the overall sample. Survivors of critical pulmonary stenosis had a functional class of 1.1, and survivors of pulmonary atresia with intact ventricular septum a functional class of 1.6. There were no differences based on the presence or absence of coronary artery to right ventricle fistulae.

CONCLUSIONS

Coronary artery to right ventricle fistulae may not be a contraindication for biventricular strategy. Patients with critical pulmonary stenosis had better outcomes compared to patients with pulmonary atresia with intact ventricular septum. The aggressive strategy of opening the pulmonary valve early on was associated with a good overall survival and correlated to a good functional class.

Myocardial strain abnormalities in fetuses with pulmonary atresia and intact ventricular septum

OBJECTIVES

Global and regional myocardial deformation have not been well described in fetuses with pulmonary atresia and intact ventricular septum (PA/IVS). Speckle-tracking echocardiography (STE), an angle-independent technique for assessing global and regional strain, may be a more sensitive way of determining ventricular systolic dysfunction compared with traditional 2D echocardiography. The aim of this study was to assess myocardial deformation in fetuses with PA/IVS compared with control fetuses and to determine if, in fetuses with PA/IVS, strain differs between those with and those without right ventricle-dependent coronary circulation (RVDCC).

METHODS

This was a retrospective analysis of fetuses with PA/IVS examined at two medical centers between June 2005 and October 2017. Left ventricular (LV) and right ventricular (RV) regional and global longitudinal strain (GLS) and strain rate were obtained using STE, and comparisons were made between fetuses with PA/IVS and gestational age (GA)-matched controls. Postnatal outcome was assessed, including the presence of RVDCC.

RESULTS

Fifty-seven fetuses with PA/IVS and 57 controls were analyzed at a mean GA of 26.5 ± 5 weeks. LV-GLS was significantly decreased in fetuses with PA/IVS compared with controls (-17.4 ± 1.7% vs -23.7 ± 2.0%, P < 0.001). LV strain rate was also significantly decreased (-1.01 ± 0.21/s vs -1.42 ± 0.20/s, P < 0.001). Fetuses with PA/IVS had decreased strain in all segments. Similarly, RV strain was significantly decreased in fetuses with PA/IVS (-11.6 ± 3.8% vs -24.6 ± 2.5%, P < 0.0001). Thirty-six patients had postnatal cardiac catheterization performed to define coronary anatomy; 10 fetuses had RVDCC. Fetuses with RVDCC had decreased LV strain compared with those without (-15.8 ± 1.2% vs -17.9 ± 1.7%, P = 0.009). RV strain was also decreased in fetuses with RVDCC vs those without (-7.0 ± 2.9% vs -12.1 ± 3.2%, P = 0.0004).

CONCLUSIONS

Fetuses with PA/IVS have decreased global and regional LV and RV strain compared with controls. The finding of decreased LV strain may be due to altered ventricular mechanics in the context of a hypertensive right ventricle and/or abnormal coronary perfusion. Moreover, fetuses that were found to have RVDCC postnatally had decreased LV and RV strain compared with those that did not. These results encourage further investigation to assess whether fetal ventricular strain could be a prenatal predictor of RVDCC. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

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.

Left ventricular function after a Fontan operation in patients with pulmonary atresia with an intact ventricular septum

OBJECTIVES

In patients with pulmonary atresia with an intact ventricular septum (PA/IVS), there are no reports about the impact of sinusoidal communication (SC) on left ventricular (LV) performance after a Fontan operation; therefore, the purpose of this study was to fill this gap in the literature.

METHODS

We performed a single-centre, retrospective study of 46 patients with PA/IVS. Nineteen patients who underwent the Fontan procedure were enrolled and divided into 2 groups: those with SC (SC group) and those without SC (N group). The 2 groups were compared in terms of postoperative cardiac function.

RESULTS

Thirteen patients were in the SC group (4 patients with right ventricle-dependent coronary circulation) and 6, in the N group. Although 2 of the patients with right ventricular (RV)-dependent coronary circulation showed focal asynergy of the LV wall, others showed no findings of myocardial infarction. The patients' preoperative age and age during the observation period after the Fontan operation did not differ. There was no difference in LV ejection fraction, cardiac index and RV and pulmonary artery pressure before and after the Fontan operation. Preoperative RV volume in the N group was greater than that in the SC group. Brain natriuretic peptide levels were higher in the SC group after the Fontan operation. On ventricular efficacy analysis, contractility was lower (1.8 ± 0.32 vs 2.5 ± 0.40 mmHg/ml/m2, P = 0.001) and ventricular efficacy was worse (1.0 ± 0.15 vs 0.86 ± 0.11, P = 0.046) in the SC group during the postoperative period.

CONCLUSIONS

Compared to patients with PA/IVS without SC, patients with PA/IVS with SC had a low cardiac contractility and decreased cardiac output efficiency after the Fontan procedure.

Strain and Rotational Mechanics in Children With Single Left Ventricles After Fontan

BACKGROUND

Left ventricular (LV) mechanics in patients with different single morphologic LV subtypes, including tricuspid atresia, double-inlet left ventricle, and pulmonary atresia with intact ventricular septum, remain poorly studied. Given that histologic studies indicate differences in LV myocardial fiber orientation, we hypothesized that this may result in altered LV mechanics. The aim of this study was to evaluate the influence of LV morphology on LV mechanics.

METHODS

Fifty-two children with single left ventricles after Fontan operation and age-matched control subjects were prospectively enrolled. Using two-dimensional speckle-tracking echocardiography, longitudinal strain was measured in the four-, three-, and two-chamber long-axis planes, and circumferential strain was measured at the basal, mid, and apical short-axis planes. Apical and basal rotation were measured, and twist and torsion were calculated. We compared strain and rotational mechanics in cases versus control subjects and among LV subtypes.

RESULTS

Compared with control subjects, subjects with single left ventricles had similar LV end-diastolic dimensions but significantly decreased ejection fractions. The single left ventricle cohort had normal global longitudinal strain (P = .20) but lower basal mean circumferential strain (P < .0001). Single left ventricle subjects had higher apical rotation (P = .0001) but decreased basal rotation (P = .0007); there was no difference in twist but increased torsion (P = .001). LV subtypes had different four-chamber (P = .01), two-chamber (P = .006), and global longitudinal strain (P = .01), lowest in the pulmonary atresia with intact ventricular septum subtype.

CONCLUSIONS

Longitudinal LV strain was preserved in children with single left ventricles after Fontan. A pattern of reduced basal circumferential strain and rotation with an increase in apical rotation and torsion in the single left ventricle cohort may be related to differences in myofiber orientation, increased fibrosis, and the impact of altered loading conditions throughout palliation. Decreased longitudinal strain in the pulmonary atresia with intact ventricular septum group may also reflect detrimental interventricular interactions.

Fetal interventions for structural heart disease

Fetal cardiac intervention (FCI) offers the potential to alter in utero anatomy and physiology. For aortic stenosis with evolving hypoplastic left heart syndrome and pulmonary atresia with intact ventricular septum with evolving hypoplastic right heart syndrome, FCI may result in maintenance of a biventricular circulation, thus avoiding single-ventricle palliation and its attendant complications. In the case of hypoplastic left heart syndrome with intact atrial septum, FCI may ameliorate in utero pathophysiology and portend a more favorable postnatal prognosis. In all cases, a detailed fetal echocardiographic assessment to identify the appropriate FCI candidate is essential. This article reviews the three aforementioned lesions for which FCI can be considered. The pathophysiology and rationale for intervention, echocardiographic assessment, patient selection criteria, and outcomes for each lesion will be reviewed. A primary focus will be the echocardiographic evaluation of each lesion.

Large right ventricular sinusoids in an infant with aorta-left ventricular tunnel and proximal right coronary artery atresia

We report a 1-month-old infant diagnosed with an aorta-left ventricular tunnel, ventricular septal defect, and right coronary atresia with right ventricular sinusoids. The patient's anatomy and physiology did not indicate right-ventricular-dependent coronary circulation, and therefore right ventricular decompression could be performed without compromising coronary perfusion during surgical correction. A detailed understanding of the coronary anatomy is critical in managing this defect when coronary anomalies are present.

Transthoracic Echocardiographic Assessment of Coronary Flow in the Diagnosis of Right Ventricular-Dependent Coronary Circulation in Pulmonary Atresia with Intact Ventricular Septum

Right ventricular-dependent coronary circulation (RVDCC) is associated with pulmonary atresia with intact ventricular septum and is defined by two or more epicardial coronary arteries with atresia or severe stenosis resulting in the dependency of coronary supply by retrograde flow. The hypothesis of this study is that coronary Doppler flow patterns on echocardiography can be used to distinguish patients with RVDCC. Between 2007 and 2016, we reviewed 16 patients with pulmonary atresia or critical pulmonary stenosis. Patients were divided into two groups, those with RVDCC (determined by angiography or pathology evaluation) and those without. Echocardiographic evaluation of the coronary arteries included 2-dimensional measurements and pulse wave Doppler flow pattern in 3 epicardial coronary arteries. Velocity-time integral (VTI) and maximal velocity (V_max) were measured and compared between the two groups. Three coronary flow patterns were demonstrated: (1) all antegrade flow, (2) antegrade to retrograde VTI flow ratio > 1, and (3) antegrade to retrograde VTI flow ratio ≤ 1. Of the 7 patients with RVDCC, 6 (86%) had evidence of flow pattern 3 in ≥ 2 of the 3 coronary arteries in contrast to 0 (0%) of the non-RVDCC patients (p = 0.001). Higher retrograde V_max was associated with RVDCC (p < 0.001) and coronary artery dilatation with Z-score ≥ + 3 was also associated with RVDCC (p = 0.02). Echocardiographic evaluation of the coronaries can be useful in identifying RVDCC. More retrograde flow in at least two coronary arteries is strongly suggestive of RVDCC. Dilatation of the coronary arteries is also supportive evidence.

Pulmonary atresia with intact ventricular septum and congenital left ventricular aneurysm

Pulmonary atresia with intact ventricular septum and congenital left ventricular aneurysms are both rare, representing <1 and <0.1% of CHD, respectively. The association of left ventricular aneurysms and pulmonary atresia with intact ventricular septum has been documented in the literature, but all the previous case reports have involved children with acquired left ventricular aneurysms. We report an interesting case of a child with both pulmonary atresia with intact ventricular septum and a congenital left ventricular aneurysm. The combination of these two lesions ultimately affected the course of clinical care for the patient.

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.

Perioperative and Anesthetic Considerations in Pulmonary Atresia With Intact Ventricular Septum

Pulmonary atresia with intact ventricular septum (PA/IVS) is a rare right-heart obstructive lesion with a wide anatomic and physiologic spectrum of disease, ranging from simple membranous pulmonary valve atresia with a fully developed right ventricle (RV) to a severely hypoplastic RV and ventriculocoronary (RV-coronary) fistulas. Affected neonates are dependent on prostaglandin for adequate pulmonary blood flow. Depending on the severity of disease, treatment options range from transcatheter pulmonary valve perforation and ultimate biventricular repair to staged single-ventricle palliation. Cardiac transplantation is recommended in the most severe cases. This review will discuss the perioperative and anesthetic management of patients with PA/IVS and highlight the challenges in management.

Hybrid Palliation for Ductal-Dependent Systemic Circulation

We reviewed our hybrid palliation experience for 91 neonates, with ductal-dependent systemic circulation, born between August 2007 and October 2015. For analysis, we stratified the 91 patients by a risk factor (RF) score and divided them into three groups: (1) high-risk two-functional ventricles (2V) median RF score of 3 (N = 20); (2) low-risk one-functional ventricle (1V) RF score 0-1 (N = 32); and (3) high-risk 1V RF score ≥2 (N = 39). Midterm survival (median 4 years) by group was: (1) 95 %, (2) 91 %, and (3) 15 %, (p = 0.001). In conclusion, hybrid palliation was associated with excellent midterm results for high-risk 2V and low-risk 1V patients with ductal-dependent systemic circulation. In contrast, high-risk 1V patients had significantly worse outcomes.

Pulmonary atresia with intact ventricular septum and coronary cameral fistulae: an unusual finding of a subsystemic right ventricle

We report the case of a neonate with pulmonary atresia with intact ventricular septum and coronary cameral fistulae despite having a subsystemic right ventricle. We review the literature on coronary cameral fistulae in this disease and right ventricle-dependent coronary circulation. We discuss the potential consequences of this physiology, including risk of adverse cardiovascular events that may impact risk stratification and surgical palliation.

Pediatric Heart Transplantation: Report from a Single Center in China

BACKGROUND

Although heart transplantation (HTx) has become a standard therapy for end-stage heart diseases, experience with pediatric HTx is limited in China. In this article, we will try to provide the experience with indications, complications, perioperative management, immunosuppressive therapy, and survival for pediatric HTx based on our clinical work.

METHODS

This is a retrospective chart review of the pediatric patients undergoing HTx at Department of Cardiovascular Surgery of Union Hospital from September 2008 to December 2014. We summarized the indications, surgical variables, postoperative complications, and survival for these patients.

RESULTS

Nineteen pediatric patients presented for HTx at Union Hospital of Tongji Medical College, of whom 10 were male. The age at the time of transplantation ranged from 3 months to 18 years (median 15 years). Patient weight ranged from 5.2 kg to 57.0 kg (median 38.0 kg). Pretransplant diagnosis included cardiomyopathy (14 cases), complex congenital heart disease (3 cases), and tumor (2 cases). All recipients received ABO-compatible donor hearts. Postoperative complications occurred in 12 patients, including cardiac dysfunction, arrhythmia, pulmonary infection, renal dysfunction, and rejection. Two of them experienced cardiac failure and required extracorporeal membrane oxygenation. The immunosuppression regimen was comprised of prednisone, a calcineurin inhibitor, and mycophenolate. All patients recovered with New York Heart Association (NYHA) Class I-II cardiac function and were discharged. Only one patient suffered sudden death 19 months after transplantation.

CONCLUSION

Orthotopic HTx is a promising therapeutic option with satisfying survival for the pediatric population in China with end-stage heart disease.