Abstract 10725: Prevalence and Impact of Recurrent Rejection on Graft Loss in Pediatric Heart Transplant Recipients: A Pediatric Heart Transplant Society Multi-Institutional Analysis

Abstract

Introduction: Rejection remains a significant cause of graft loss after heart transplantation. The current prevalence of recurrent rejection and its impact on graft loss after pediatric heart transplantation is unknown. Methods: All pediatric heart transplants between 1/2000-6/2020 in the Pediatric Heart Transplant Society database were included. Rejection was defined as a clinical event determined by biopsy, echocardiogram or clinical findings that resulted in augmentation of immunosuppression. Recurrent rejection was defined as ≥ 2 episodes of rejection after heart transplant. Freedom from recurrent rejection in the early (2000-2009) and current (2010-2020) era were compared. Multiphase parametric hazard modeling was utilized to understand the effects of each additional episode of rejection on graft loss in addition to identifying other risk factors. Results: Of 6342 heart transplants during the study period, 3921 (62%) had 0, 1386 (21%) had 1 and 1035 (17%) had ≥2 rejection episodes. In the current era, recurrent rejection is less frequent [468/4206 (11.1%) vs. 567/2136 (26.5%); p<0.001] (Figure A). Recurrent rejection increased probability of graft loss in both the unadjusted and multivariate adjusted analysis (HR 1.68; 95% CI 1.61-1.75, p<0.001) (Figure B and Table). Other risk factors for graft loss after pediatric HT are outlined in the Table. Conclusions: Currently, recurrent rejection is experienced by 1 in 10 pediatric HT recipients. Each additional episode of rejection post-HT confers an increasing risk for graft loss. Identifying risk factors for recurrent rejection is paramount to improving graft longevity.