Clinical Research Directory

Inclusion criteria (must all met) 1. Patients \>19 years old 2. Patients who underwent DES implantation 12 months (-1 to +5 months) previously. 3. High risk characteristics (clinical or lesion) for ischemic events (must at least one) High risk patients; clinical criteria 1. Acute coronary syndrome 2. Previous history of cerebrovascular accidents 3. History of peripheral artery intervention 4. Heart failure (left ventricular ejection fraction ≤40%) 5. Diabetes treated with medication 6. Chronic renal insufficiency including end-stage renal diseases High risk lesions; angiographic or procedural criteria 1. Left main diseases 2. Bifurcation lesions 3. Chronic total occlusion 4. In-stent restenotic lesions 5. Graft lesions 6. Diffuse long lesions requiring total stent length ≥28 mm 7. Calcified lesions requiring atherectomy 8. Multivessel coronary artery disease with multiple stents 9. Small vessel disease requiring stent diameter of ≤2.5 mm Exclusion criteria 1. Age\> 80 years 2. Pregnant women or women with potential childbearing 3. Life expectancy \< 1 year 4. Refusal or inability to understand of informed consent 5. Need for chronic oral anticoagulation 6. History of major bleeding within 3 months prior to randomization