A New Strategy Regarding Discontinuation of Dual Antiplatelet

Inclusion Criteria: * Coronary artery disease including stable angina, unstable angina, acute non-ST elevation myocardial infarction and acute ST elevation myocardial infarction * Age 20 years of older * Patients with typical chest pain or evidences of myocardial ischemia (e.g., stable, unstable angina, silent ischemia and positive functional study or reversible changes in the electrocardiogram (ECG) consistent with ischemia * Patients with signed informed consent * Lesion and stent length for ACS and DM subgroup : Length of single lesion \< 24 mm and, Summation of total length of all inserted DES in 3 vessel \< 60 mm * Lesion and stent length for ACS and DM subgroup : Length of single lesion \< 24 mm and, Summation of total length of all inserted DES in 3 vessel \< 60 mm * Lesion and stent length for long lesion subgroup : Length of single stent per single lesion \> 28 mm and, Summation of total length of all inserted DES in 3 vessel ≤ 90 mm, Possible overlapping stent * Lesion and stent length for short lesion subgroup : Length of single lesion \< 24 mm and, Summation of total length of all inserted DES in 3 vessel \< 60 mm * Significant coronary artery stenosis (\>50% by visual estimate) considered for coronary revascularization with stent implantation * Reference vessel diameter of 2.5 to 4.0 mm by operator assessment * Lesion success (30% or less residual stenosis by visual assessment over the entire stent length, with TIMI-3 flow and no more than an NHLBI type B peri-stent dissection Exclusion Criteria: * Contraindication to anti-platelet agents \& bleeding history within prior 3 months * Known hypersensitivity or contraindication to any of the following medications: Heparin, Aspirin, Clopidogrel, limus related drug * Prior history of the following presentations : Cerebral vascular accident (not including transient ischemic attack, Peripheral artery occlusive diseases, Thromboembolic disease, Stent thrombosis * Severe hepatic dysfunction (3 times normal reference values) * Significant renal dysfunction (Serum creatinine \> 2.0 mg/dl) * Significant leukopenia, neutropenia, thrombocytopenia, anemia, or known bleeding diathesis * Cardiogenic shock * LVEF \< 40% * Pregnant women or women with potential childbearing * Life expectancy 3 year * Overlapped DESs(only long lesion subgroup is possible overlapping) * Left main disease requiring PCI * Bifurcation lesion with 2-stent technique * Target lesions with in-stent restenosis at the stented segment of DES or BMS * Lesions with chronic total occlusion * History of PCI with DES * In-stent restenosis lesion