A sTudy of Low Dose vs Standard Dose of tIcaGrelor on Platelet Function After intErvention for Acute Coronary syndRome in Diabetes Mellitus Patients

Inclusion Criteria: 1. Subject must be at least 18 years of age and less than 90 years old 2. Patients should have undergone successful percutaneous coronary intervention with drug-eluting stent for acute coronary syndrome with diabetes mellitus. 3. Subject understand the study requirements and the treatment procedures and 4. provided informed consent before the procedure Exclusion Criteria: 1. Female of childbearing potential, unless a recent pregnancy test is negative, who possibly plan to become pregnant any time after enrollment into this study 2. Active bleeding 3. Known hypersensitivity or contraindication to study medications 4. Female of childbearing potential, unless a recent pregnancy test is negative, who possibly plan to become pregnant any time after enrollment into this study 5. Non-cardiac co-morbid conditions are present with life expectancy \<2 year or that may result in protocol non-compliance (per site investigator's medical judgment). 6. Subjects with Cerebral hemorrhage history 7. Subjects with stroke history in half a year 8. subjects with active malignant tumor 9. subjects with whom oral anticoagulants are needed 10. Other conditions which the investigators think not applicable to the study.