A Study of Low and Standard-dose Ticagrelor After Intervention for ACS Patients

Inclusion Criteria: 1. Subject must be at least 18 years of age 2. Patients should have undergone successful percutaneous coronary intervention with drug-eluting stent for acute coronary syndrome 3. Subject understand the study requirements and the treatment procedures and 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. 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). 5. Subjects with Cerebral hemorrhage history 6. Subjects with stroke history in half a year 7. subjects with malignant tumor 8. subjects with whom oral anticoagulants are needed