Rationale and design of the dual antiplatelet therapy study, a prospective, multicenter, randomized, double-blind trial to assess the effectiveness and safety of 12 versus 30 months of dual antiplatelet therapy in subjects undergoing percutaneous coronary intervention with either drug-eluting stent or bare metal stent placement for the treatment of coronary artery lesions

Background: Dual antiplatelet therapy with aspirin and thienopyridines (clopidogrel or prasugrel) is required after placement of coronary stents to prevent thrombotic complications. Although current clinical practice guidelines recommend 12-month treatment after drug-eluting stent placement, even longer durations may prevent thrombotic events.

Study design: The Dual Antiplatelet Therapy (DAPT) Study is comparing the benefits and risks of 12 versus 30 months of dual antiplatelet therapy in preventing stent thrombosis or major adverse cardiovascular and cerebrovascular events in subjects undergoing percutaneous coronary intervention (PCI) for the treatment of coronary artery obstructive lesions. The DAPT Study is a multicenter, international, randomized, double-blind, placebo-controlled trial that will enroll 15,245 subjects treated with drug-eluting stent (DES) and 5,400 subjects treated with bare-metal stents (BMS). All subjects will receive 12 months of open-label thienopyridine treatment in addition to aspirin. After 12 months, subjects who are free from death, myocardial infarction, or stroke (MACCE), repeat revascularization, and GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) moderate or severe bleeding events will be randomized to receive either 18 additional months of thienopyridine (clopidogrel or prasugrel) (30 month DAPT arm) or placebo (12 month DAPT arm) plus aspirin. Coprimary end points are MACCE and stent thrombosis. The primary safety end point is GUSTO moderate or severe bleeding.

Conclusions: This randomized trial is designed to define the relative safety and effectiveness of 12 versus 30 months of dual antiplatelet therapy across the broad spectrum of patients receiving coronary stents.