Extended antiplatelet therapy with clopidogrel alone versus clopidogrel plus aspirin after completion of 9-to 12-month dual antiplatelet therapy for acute coronary syndrome patients with both high bleeding and ischemic risk. Rationale and design of the OPT-BIRISK double-blinded, placebo-controlled randomized trial

Background Dual antiplatelet therapy with aspirin and a P2Y12 inhibitor is the cornerstone for prevention ischemic events in patients with acute coronary syndromes (ACS) and undergoing percutaneous coronary intervention. However, the optimal antiplatelet strategy for ACS patients with both high bleeding and high ischemic risks is unclear. Study design The OPT-BIRISK trial is a multicenter, double-blinded, placebo-controlled randomized study designed to test the superiority of extended antiplatelet therapy with clopidogrel monotherapy compared with aspirin and clopidogrel for reduction of bleeding events in ACS patients with both high bleeding and high ischemic risks ("bi-risk"). A total of 7,700 patients who completed 9- to 12-month dud antiplatelet therapy after new-generation drug-eluting stent implantation for the treatment of ACS will be randomized to receive clopidogrel monotherapy or aspirin plus clopidogrel for 9 months followed by aspirin monotherapy for 3 months. The primary end point is Bleeding Academic Research Consortium type 2, 3, or 5 bleedings at 9 months after randomization. The key secondary end point is major adverse cardiac and cerebral events at 9 months after randomization, defined as a composite of all-cause death, myocardial infarction, stroke, or coronary artery revascularization. Conclusions OPT-BIRISK is the first large-scale randomized trial aimed to explore the optimal antiplatelet strategy for birisk ACS patients after percutaneous coronary intervention in current clinical practice. The results will add evidence regarding de-escalation antiplatelet therapy for patients at special risk.