Optical Coherence Tomography to Evaluate Ticagrelor and Clopidogrel

Inclusion Criteria: * Provision of informed consent prior to any study specific procedures; * Men and women 18 years and older;. * Established indication to PCI according to the guidelines of American Heart Association and American College of Cardiology; * Native coronary lesion suitable for drug-eluting stent placement and OCT imaging. Exclusion Criteria: * Pregnancy and breast feeding mother; * Co-morbidity with an estimated life expectancy of \< 50 % at 12 months; * Scheduled major surgery in the next 6 months; * Inability to follow the protocol and comply with follow-up requirements or any other reason that the investigator feels would place the patient at increased risk; * Previous enrolment in this study or treatment with an investigational drug or device under another study protocol in the past 30 days * Cardiogenic shock * Previous subacute or late coronary stent thrombosis * Known allergy against ticagrelor, or against clopidogrel, or aspirin * History of major hemorrhage (intracranial, gastrointestinal, etc.) * Active pathological bleeding * Acute or chronic hematologic disorder including a Hemoglobin less than 10 g/L or a platelet count less than 10×109/L before procedure * Any history of Severe renal or hepatic dysfunction (hepatic failure, cirrhosis, portal hypertension and active hepatitis); * Neutropenia, * thrombocytopenia; * Known acute pancreatitis * Arterial aneurysm, arterial/venous malformation and aorta dissection. * Culprit lesion within the proximal 10 mm of the right or left coronary artery * Saphenous vein grafts * Lesion length \> 30 mm * Involves a side branch ≥2.0 mm in diameter by visual estimate which requires treatment * In-stent restenotic lesions * Thombus-containing lesions