Early aspirin initiation following heart transplantation is associated with reduced risk of allograft vasculopathy during long-term follow-up

Aim: Cardiac allograft vasculopathy (CAV) is a major cause of morbidity and mortality after heart transplantation (HT). Enhanced platelet reactivity is a contributing factor. We aimed to investigate the association between early initiation of aspirin therapy post-HT and the 15-year risk of the development of CAV. Methods: We studied 206 patients who underwent HT between 1991 and 2016. Multivariate Cox proportional hazards regression modeling was employed to evaluate the association between early aspirin initiation and the long-term risk of CAV. Results: Ninety-seven patients (47%) received aspirin therapy. At 15 years of follow-up, the rate of CAV was lowered by sixfold in patients treated with aspirin compared with the non-treated patients: 7% vs 37% (log-rank P-value<.001). The corresponding rates of the combined end-point of CAV or death were also lower in patients treated with aspirin, compared with the non-treated patients: 42% vs 78% (log-rank P <.001). Consistently, multivariate analysis showed that early aspirin therapy was associated with a significant 84% (P <.001) reduction in CAV risk, and with a corresponding 68% (P <.0001) reduction in the risk of the combined end-point of CAV or death. We further validated these results using a propensity score-adjusted Cox model. Conclusions: Early aspirin initiation is independently associated with a significant reduction in the risk of CAV.