PLATELET-AGGREGATION AND HDL CHOLESTEROL ARE PREDICTIVE OF ACUTE CORONARY EVENTS IN HEART-TRANSPLANT RECIPIENTS

Background Sudden death (SD) and acute myocardial infarction (AMI) are the main complications limiting long-term survival after heart transp lantation (HT). They are unpredictable and, at present, unpreventable. Platelet aggregation (PA) has recently emerged as a significant progn ostic indicator in nontransplanted coronary disease patients. The main purpose of the present study was to evaluate to what extent PA could predict SD and AMI in long-term survivors of HT independently of serum lipid levels. Methods and Results We studied 207 patients. Al receive d triple immunosuppressive therapy. During follow-up, the incidence of SD and AMI was determined, and the independent role of PA as predicto r was evaluated with other usual risk factors by a Cox multivariate re gression model. There were 11 SDs and 14 AMIs after an average follow- up of 642 days, giving an average incidence rate of 7.3 events per yea r per hundred patients. By univariate analysis, the most potent predic tors were ADP-induced platelet aggregation (positive association) and total cholesterol (negative association). Age and length of time since transplant were not predictors. By multivariate analysis, only the se condary wave of ADP-induced platelet aggregation (P=.001) and high-den sity lipoprotein cholesterol (P=.03) were independent predictors. The relative risk of SD or AMI based on a comparison between patients with high (>36%) or low (<36%) ADP-induced platelet aggregation was 4.3 (9 5% confidence interval, 1.9 to 9.5, P=.0001). Conclusions This study p rovides the first demonstration of an association between increased pl atelet aggregation and subsequent SD or AMI in HT recipients. It sugge sts that platelets and thrombosis also are implicated in the pathogene sis of AMI and SD in HT recipients. Identification of a safe and effec tive antiplatelet therapy should be actively pursued.