Cilostazol is an kind of oral antiplatelet agent with a rapid onset of action that selectively inhibits phosphodiesterase III, a mechanism different from adenosine diphosphate (ADP) receptor antagonists. Previous studies had suggested that cilostazol has lipid-modifying and vasodilating effects in addition to antiplatelet effects. From those experimental and clinical backgrounds, we assumed that triple antiplatelet therapy with aspirin, clopidogrel, and cilostazol might have a beneficial effect on the prevention of atherothrombosis complications following coronary stenting. Therefore, we evaluated the safety and efficacy of triple antiplatelet regimen of aspirin, clopidogrel and cilostazol compared with dual antiplatelet regimen of aspirin and clopidogrel in patients with acute coronary syndrome undergoing successful coronary artery stenting.

Patients undergoing successful coronary stenting were divided into dual antiplatelet therapy (aspirin plus clopidogrel) and triple antiplatelet therapy (aspirin and clopidogrel plus cilostazol) groups. All enrolled patients in triple regimen group will receive cilostazol 100mg, b.i.d., for 6 months in addition to standard dose and duration of aspirin and clopidogrel for post-PCI. The primary endpoints included death, myocardial infarction, target lesion revascularization, stent thrombosis within 30 days, binary restenosis at six month and major adverse cardiac events (MACE) at one year. The secondary endpoints were side effects of study drugs, including major bleeding, vascular complication, hypersensitivebility, and bleeding complications. The study will be powered to test the hypothesis that triple antiplatelet therapy is better than dual antiplatelet therapy.