Abstract 13291: Impact of VAD Support Duration on Pediatric Heart Transplant Outcomes

Abstract

Introduction: There is wide variability in the timing of heart transplant (HT) listing and consideration of organ offers after ventricular assist device (VAD) implant in children. While some centers wait weeks or months before proceeding with HT, others accept donor hearts within days of VAD surgery. We sought to determine if HT within 30 days of VAD implant impacts post-HT outcomes when compared to HT after ≥30 days of VAD support. Methods: Patients on VAD support prior to HT were extracted from the Pediatric Heart Transplant Study database. The primary endpoints were post-HT length of hospital stay (LOS) and one-year survival. Confounding was addressed by propensity score weighting using inverse probability of treatment. Propensity scores were calculated based on age at VAD implant, blood type, primary cardiac diagnosis, decade, VAD type, and allosensitization status. Group balance was verified with standardized differences. Results: A total of 1138 children underwent VAD implant prior to HT between 2000-2019 (Table 1). Most underwent HT ≥30 days after VAD (71%). The majority (70%) had an LVAD alone. Infants accounted for 22% of both groups, while those 1-11 years were 46% of the ≥30-day group and patients ≥12 years made up 42% of <30-day group (p=0.001). There was no difference in the prevalence of congenital heart disease vs. cardiomyopathy (p=0.7) or high allosensitization status (p=0.8) between groups. Post-HT LOS was similar between groups (23 vs. 21 days in <30 vs. ≥30 days, p=0.07). One-year survival was 90.5% in the <30-day group vs. 94.5% in ≥30 days (adjusted mortality HR 1.81, 95% CI 1.15-2.86, p=0.01). Conclusions: In this large study of children undergoing HT after VAD, we found lower one-year survival in patients on VAD support for <30 days prior to HT compared to those on VAD for ≥30 days before HT. These findings suggest that a strategy of delayed HT listing following VAD implant may favorably impact post-HT survival in the pediatric population.