Residual platelet reactivity, bleedings, and adherence to treatment in patients having coronary stent implantation treated with prasugrel

Abstract

Recent guidelines have recommended the use of aspirin and prasugrel in patients with acute coronary syndromes undergoing percutaneous coronary intervention. However, prasugrel use has been evaluated only in randomized trials. This study sought to evaluate bleeding rates and adherence to treatment in "real-world" patients treated with prasugrel. In total 298 consecutive patients 68 ± 10 years old (31% >75 years old) underwent stent implantation and received prasugrel therapy. Indications to prasugrel therapy were (1) ST-elevation acute myocardial infarction (41%), (2) drug-eluting stent implantation in diabetics (24%), (3) stent thrombosis (3%), (4) left main coronary artery drug-eluting stent implantation (6%), and (5) percutaneous coronary intervention in patients with high residual platelet reactivity on clopidogrel therapy (26%). All patients received a loading of prasugrel 60 mg. Patients ≥75 years old and with body weight ≤60 kg received a maintenance dose of 5 mg/day (10 mg/day for all the other patients). Follow-up data including adherence to prasugrel therapy were collected by telephone interviews or outpatient visits. Minimal follow-up length was 6 months (mean 9 ± 3). Major, minor, and minimal bleedings (Thrombolysis In Myocardial Infarction criteria) occurred in 2.7%, 4.7%, and 15.1% of enrolled patients. Low residual platelet reactivity (p = 0.001) and female gender (p = 0.29) were independent predictors of bleeding events. The most frequent minimal bleeding event was epistaxis. Only 8 patients (2.7%) permanently discontinued prasugrel therapy because of bleeding events (n = 4), possible side effects (n = 2), or medical decisions not associated with bleeding or side effects (n = 2). Fourteen patients (4.7%) temporarily discontinued prasugrel (average 6.5 days) mainly because of surgical procedures. No definite or probable stent thrombosis occurred, although 3 patients develop de novo myocardial infarction and 1 an ischemic stroke. There were 11 deaths because of heart failure or refractory cardiogenic shock in 9, pulmonary embolism in 1, and cancer in 1. In conclusion, in clinical practice, major and minor bleeding event rates associated with prasugrel therapy are comparable to those reported in controlled randomized trials. The minimal bleeding event rate is higher than reported but does not seem to affect adherence to treatment.