Early aspirin use and the development of cardiac allograft vasculopathy in pediatric heart transplant recipients: A pediatric heart transplant society analysis.

Abstract

Cardiac allograft vasculopathy (CAV) remains a leading cause of graft loss in pediatric heart transplant (HTx) recipients. Adult literature suggests that aspirin (ASA) use in the early post-HTx period may reduce the risk of CAV. This study aimed to determine the impact of early ASA use on the development of CAV in pediatric HTx recipients. All subjects <17 years of age at time of primary HTx who survived ≥3 years without evidence of CAV were identified for inclusion from the Pediatric Heart Transplant Society database (1996-2019). Early ASA use was defined as ASA started within the first 3 years post-HTx and was classified as continuous or intermittent. Frequency of ASA use was described across centers. Kaplan-Meier method assessed freedom from CAV and overall graft survival. Multiphase parametric hazard analyses and propensity score matched analysis were used to identify independent risk factors. 3,011 patients were included with 387 (13%) receiving continuous ASA, 676 (22%) receiving intermittent ASA, and 1,948 (65%) receiving no ASA. ASA use was highly variable across centers (0%-100%). At baseline patients receiving continuous ASA therapy demonstrated inferior graft survival (p < 0.001) and worse freedom from CAV (p=0.002), but with lower CAV grades (p=0.05). In multiphase parametric hazard modeling continuous ASA use was not independently associated with CAV, but remained associated with inferior graft survival. Propensity-matched sub-analysis between continuous and no ASA groups demonstrated no difference in freedom from CAV or overall graft loss. ASA use varies widely across pediatric HTx centers. Early ASA use did not reduce the risk of CAV or graft loss in pediatric heart transplant recipients.