Increasing Pretransplant Panel Reactive Antibodies Worsens Survival in A Contemporary Heart Transplantation Cohort

Abstract

Background Allosensitization as measured by presence of panel reactive antibodies (PRA) negatively impacts survival in adult heart transplant (HT) recipients. Questions remain whether these trends remain in more contemporary cohorts. We examined the interaction between long-term survival and pre-transplant PRA level in HT recipients from 2000-2018. Methods We identified adult HT recipients between 2000 and 2018 who had a pretransplant PRA in the Scientific Registry of Transplant Recipients. Study cohort was divided into groups with PRA levels; group with 0%, 1-10%, 11-24% and ≥25% PRA levels. We compared 3- and 5-year survival with the Kaplan-Meier method. We constructed Cox proportional hazards regression models to determine the risk adjusted influence of PRA category and PRA as a continuous value on survival. Results We included 24,655 HT recipients. PRA was 0% in 17,391 (70.5%) recipients, 1-10% in 3,331 (13.5%) recipients, 11-24% in 1,330 (5.4%) recipients, and ≥25% in 2,603 (10.6%) recipients. Patients with a PRA ≥25% were younger, had fewer comorbidities, and were more likely to be on ECMO or LVAD prior to HT. Unadjusted 3- and 5-year estimated survival was lower with increasing PRA category (Figure). After risk-adjustment, 5-year survival was higher for the 0% cohort compared to the 1-10% (HR 1.10, 95% CI 1.02-1.18), 11-24% (HR 1.20, 95%CI 1.08-1.34), and ≥25% (HR 1.16, 95% CI 1.07-1.26). When analyzed continuously, increasing PRA was associated with a lower survival (HR 1.003, 95% CI 1.002-1.005). Sensitivity analysis of those transplanted from 2013-2018 showed similar results. Conclusions In this contemporary cohort of HT recipients, increasing pretransplant PRA was associated with lower survival. Given the appreciable portion of HT recipients with elevated PRA, improvements in recipient selection and HT management may help improve outcomes.