Sitagliptin Utilization in Diabetic Patients with Coronary Artery Disease for Improving Cardiovascular Outcomes (SUPERIOR study)

INTERVENTION: DPP4 inhibitor (sitagliptin) treatment group Intensification of conventional treatment group CONDITION: Coronary artery disease, Type 2 diabetes mellitus PRIMARY OUTCOME: Cardiovascular events (composite of cardiovascular death, non‐fatal myocardial infarction, unstable angina pectoris, non‐fatal ischemic stroke, hospitalization fordecompensated heart failure, coronary revascularization, deep vein thrombosis, pulmonary embolism, or hospitalization for peripheral artery disease) SECONDARY OUTCOME: All cause death; Hypoglycemic and hyperglycemic coma Event ; The change of parameters (GLP‐1, BNP, high sensitivity CRP, IL‐6 and other biochemical markers, blood pressure, body weight, heart rate, and waist circumference); Coronary angiography finding (Percent atheroma volume, the change of percent atheroma volume); The change of parameters in echocardiography ; Endothelial function assessed by reactive hyperemia peripheral arterial tonometry INCLUSION CRITERIA: 1) Type 2 diabetes mellitus patients with acute coronary syndrome and stable condition. 2) Coronary artery disease patients with type 2 diabetes mellitus Patients with coronary artery disease documented by CAG or CT with organic coronary stenosis of >50% in major coronary arteries.