Background: Data on bleeding events in Japanese patients with acute coronary syndrome (ACS) are insufficient. In addition, the efficacy and safety of a maintenance dose of prasugrel 2.5 mg/day in high bleeding risk patients are unknown.Methods and Results:We prospectively enrolled 1,167 consecutive patients with suspected ACS and undergoing percutaneous coronary intervention. The maintenance dose of prasugrel 2.5 mg/day was prescribed for patients with a low body weight (≤50 kg), elderly (≥75 years), or renal insufficiency (eGFR ≤30 mL/min/1.73 m2). In-hospital events were assessed in 992 ACS patients treated with drug-eluting stents. Excluding 29 in-hospital deaths, out-of-hospital events were assessed in 963 ACS patients. The primary safety outcome measure was major bleeding (Bleeding Academic Research Consortium types 3 and 5). The incidence of in-hospital major bleeding was 3.4%. Multivariate analysis showed that being elderly, low body weight, renal insufficiency, stroke history, femoral approach, and mechanical support usage were independent predictors of in-hospital major bleeding. The cumulative 1-year incidence of out-of-hospital major bleeding was not significantly different between the prasugrel 2.5 mg/day (n=284) and 3.75 mg/day (n=487) groups (1.6% vs. 0.7%, log-rank P=0.24). That of out-of-hospital definite or probable stent thrombosis was 0% in both groups.
Conclusions: The maintenance dose of adjusted prasugrel 2.5 mg/day seems to be one option in ACS patients at high bleeding risk.
Keywords: Acute coronary syndrome; Drug-eluting stents; Percutaneous coronary intervention; Prasugrel.