A Randomized Comparison of CLOpidogrel Monotherapy Versus Extended Dual-antiplatelet Therapy Beyond 12 Months After Implantation of Drug-eluting StEnts in High-risk Lesions or Patients; A-CLOSE Trial

Patients at high risk for either ischemic or bleeding complications, but who were stable without clinical evetns for 12 months after DES implantation will be included in this study. Eligible patients will be randomized to continue DAPT (aspirin plus clopidogrel) for further 24 months or to change to single antiplatelet therapy with clopidogrel (clopidogrel-alone). Randomization will be stratified according to 1) clinical presentation (acute coronary syndrome or stable coronary artery disease) and 2) age (≥75 or <75). Baseline clinical and angiographic characteristics, laboratory findings will be assessed at the time of randomization. All patients will provide informed consent on their own initiative. All of study subjects will be have an outpatient visit as scheduled in outpatient clinic. Occurrence of study endpoints will be documented at clinical visit or telephone interview every 6 months up to 24 months after randomization. Antiplatelet drugs will be open-label and prescribed by attending physician.