Pediatric Cardiology

Pulmonary Atresia with Intact Ventricular Septum: Midterm Outcomes from a Multicenter Cohort. Iliopoulos I, Mastropietro CW, Flores S, Cheung E, Amula V, Radman M, Kwiatkowski D, Puente BN, Buckley JR, Allen KY, Loomba R, Karki KB, Chiwane S, Cashen K, Piggott K, Kapileshwarkar Y, Gowda KMN, Badheka A, Raman R, Zang H, Costello JM; Collaborative Research from the Pediatric Cardiac Intensive Care Society Investigators. Pediatr Cardiol. 2024 Apr;45(4):847-857. doi: 10.1007/s00246-022-02954-5. Epub 2022 Jun 25. PMID: 35751685 Commentary from Dr. Anna Tsirka (Hartford, CT, USA), section editor of Pediatric and Fetal Cardiology Journal Watch Take Home Message This multi-center, retrospective study reviewed outcomes of neonates with PA-IVS treated between 2009 and 2019 in 19 major US hospitals. They found that mortality remains high (close to 20% at 5 years). TV Z-score is significantly associated with increased probabilities of biventricular repair, while right ventricular coronary dependency and left, but not right, coronary atresia significantly worsens transplant-free survival.  Introduction Pulmonary atresia with intact ventricular septum (PAIVS) is a rare congenital heart lesion with substantial morphologic heterogeneity, which drives widely variable management strategies and subsequent outcomes. Treatment is individualized, dependent on coronary anatomy, and size of right sided structures. Potential final end-states for patients with PAIVS include a biventricular repair, a one-and-a half ventricular repair, a Fontan, cardiac transplantation, or death.  The primary objective of this study was to describe medium-term outcomes for a contemporary multicenter cohort of patients with PAIVS, and identify factors associated with attainment of each end-state and evaluate the effect of RVDCC and coronary atresia on transplant-free survival. Methods This was a multicenter retrospective cohort study across 19 United States hospitals affiliated with Collaborative Research from the Pediatric Cardiac Intensive Care Society (CoRe-PCICS). All neonates (age less than 30 days) with PAIVS admitted in one of the participating centers from 01.01.2009 until 01.01.2019 were included. Patients with any blood flow across the pulmonary valve and those with any size ventricular septal defects were excluded. Additionally, patients with Ebstein’s anomaly or severely dysplastic tricuspid valve were also excluded. Right ventricular dependent coronary circulation (RVDCC) was based on the assessment of the local team. The primary endpoint was the cumulative risk of the five mutually exclusive end-states (biventricular, one-and-a half ventricular, Fontan, transplant, and death). The secondary end point was transplant-free survival. Results N of 295 neonates were included, 11% of which had a chromosomal anomaly. 46% had normal coronaries, while 54% had RV to coronary artery fistulas. 29% were deemed to have RV dependent coronary circulation and 6.6% had coronary atresia.   Median duration of follow up was 4.9 years. At the end of the follow-up, 76 patients (26%) remained in mixed circulation. Mortality occurred in 54 patients (18.3%): 16 patients (5.4%) died prior to any intervention, 23 patients (8.2%) died post-procedure prior to hospital discharge, and 15 patients (5.1%) died after discharge following their initial neonatal hospitalization. The cumulative risk of death was 16.9%, 17.2%, 18.8%, and 19.5% at 1, 2, 5 years, and end of study period, respectively.  Figure one demonstrates the incidence of the five competing outcomes over time.  A sub-distribution hazard model analysis indicated that increase in TV Z-score was associated with a greater chance of achieving a biventricular repair [hazard ratio (HR) 2.03, (95% CI 1.68, 2.46) per unit increase of TV Z-score], whereas the presence of RVDCC was associated with a higher likelihood of heart transplantation [HR 9.15 (95% CI 2.76, 30.27)]  A TV z score below -1.6 was more likely to result in a Fontan circulation while a TV z score over -1.6 was more likely to result in a biventricular circulation.  Similarly, higher TV Z-score decreases the odds of death or transplantation [OR 0.46, (95%CI  0.29, 0.75)], whereas the presence of coronary atresia increases the odds of death or transplantation [OR 3.75, (95%CI 1.46, 9.61)]. The table below depicts the risk factors for death or transplantation:  Finally, figure 5 describes the effect of coronary dependent circulation and coronary atresia on transplant free survival. Transplant-free survival at 25 months after the initial neonatal procedure was 84.5% (95% CI 79.2%, 90.1%) for patients without RVDCC, 49.0% (95% CI 37.6%, 63.9%) for patients with RVDCC and normal coronary ostia, 57.1% (95% CI 36.3%, 89.9%) for patients with RVDCC and right atresia, and 20.0% (95% CI 7.3%, 55.0%) for those with RVDCC and left coronary atresia (log-rank p among groups < 0.001).  Conclusions:  In this contemporary cohort of neonates with PA/IVS, overall survival is improving, surpassing 80% at 5 years, however RVDCC and left coronary atresia have a significant negative impact on transplant-free survival.   In this cohort, only 15% of patients achieved biventricular repair. A TV z-score of − 1.6 is the crossing point above which a biventricular circulation is more likely to be achievable, but not guaranteed.  The study is limited by its retrospective and multi center nature, as each center had different practice biases and procedures.