Abstract 13448: Time Course and Predictors of Renal Function Decline After Pediatric Heart Transplantation: A PHTS Multi-Institutional Analysis

Abstract

Introduction: Decline in renal function can impact both the management and outcomes of pediatric heart transplantation (HTx). Initial renal function decline may be subclinical and underappreciated. We sought to identify the time course and predictors of decline in renal function and the impact of these changes on HTx outcomes. Methods: The Pediatric Heart Transplant Society (PHTS) database was queried to identify HTx recipients at participating centers from 1996 to 2019 with at least 1 year of follow-up. Patients with simultaneous or previous kidney transplant were excluded. Renal function was measured by modified Schwartz formula eGFR on annual follow-up forms and stratified into eGFR groups by National Kidney Foundation chronic kidney disease staging guidelines. “Initial renal function decline” was defined as the initial drop by at least one eGFR group relative to stage at 1 year post transplant (“baseline”). Results: Of the 5,250 patients who met inclusion criteria, initial renal function decline occurred, relative to baseline, in 7.4%, 18.7%, and 55.7%, by 1, 5, and 10 years of follow up, respectively (Figure A). eGFR group distribution for the cohort progressively worsened over the follow up period (Figure B). On multivariate Cox modeling, risk factors for renal function decline were increased BSA at 1 year post-transplant (HR 1.24 [1.02, 1.52]), acute rejection with hemodynamic compromise (HR 1.24 [1.10, 1.39]), and Black race (HR 1.21 [1.08, 1.36]) with the use of tacrolimus (vs cyclosporine) being protective (HR 0.77 [0.69, 0.85]). Patients whose eGFR was < 30 mL/min at 1 year follow up had an increased risk of graft loss (P < 0.0001 compared to all other groups). Conclusions: Decline in renal function occurs progressively, affecting over 50% of HTx recipients in long term follow up, independent of renal condition at the time of HTx. Avoidance of potentially nephrotoxic events and medications must be considered at all times in the long term management of pediatric HTx.