Randomized Controlled Study of the Traditional Percutaneous Coronary Intervention and Intervention Using Optical Coherence Tomography of Incomplete Stent Adhesion and Extent of the Formation of Neointima by Resolute Zotarolimus-eluting Stent Insertion

Inclusion Criteria: * Single lesion in a Single vessel * Reference vessel diameter 2.5 - 3.5 mm * Lesion length ≤ 34 mm and ≤ 34 mm stent length * Stable angina requiring revascularization, patients with unstable angina * The patient has no difficulty to enforce the follow-up angiography * Patient is ≥ 20 years old Exclusion Criteria: * Lesions with graft vessel, thrombosis, restenosis, and bifurcation requiring 2 stents * Reference vessel diameter \< 2.5 mm or \> 4.0mm * Contraindication to anti-platelet agents * Treated with any DES within 3 months at other vessel * Creatinine level ≥ 2.0 mg/dL or ESRD * Severe hepatic dysfunction (3 times normal reference values) * Patients with LVEF \< 30% * Life expectancy 1 year * Lesions with CTO or left main * Target vessel of ST-elevation MI * Lesions requiring overlapped stenting or more than 2 DES in each vessel * Heavy calcified lesions (definite calcified lesions on angiogram) * Far distal or tortuous lesions having difficulties in OCT evaluation or follow-up OCT * Pregnant women or women with potential childbearing