Inclusion Criteria:  Age 18-80 years old; Acute coronary syndrome was diagnosed upon admission;  Must meet at least one of the following high-risk clinical criteria for bleeding:  Female Age ≥65 years old Hemoglobin≤110g/L Diabetes treated with medications (oral drugs or subcutaneous insulin injections) eGFR<60 ml/min/1.73m2 (MRDR formula) Implant a second-generation drug-eluting stent Intended treatment with dual antiplatelet therapy (aspirin + ticagrelor) after the procedure for at least 12 months  Exclusion Criteria:  Implanted with first-generation DES or bioabsorbable stent(s) during hospitalization; Patients with active pathological bleeding (such as peptic ulcer or intracranial hemorrhage); Previous drug-related bleeding requiring medications within 12 months; High potential risk of major bleeding, such as acute or chronic gastrointestinal ulcers or other gastrointestinal diseases, malignant tumors, etc.; Previous stroke; Thrombolytic therapy within 24 hours of coronary intervention; Planned surgery within 1 year; Planned coronary revascularization (surgical or percutaneous) within 90 days Allergic to ticagrelor, clopidogrel or aspirin and any excipients; Inability to tolerate 12-month DAPT (ticagrelor+aspirin) for any reason; Cardiogenic shock or hemodynamic instability; Diagnosed as active hepatitis or liver cirrhosis upon admission; Estimated survival time<12 months Suffer from a known serious progressive disease (e.g. progressive cancer, chronic obstructive lung disease, etc.;) or extremely exhausted; Hemoglobin <90g/L; Platelet count<100×109 pcs/L; Dialysis-dependent renal failure； Required use of oral anticoagulation (warfarin or other factor II or factor X inhibitors); Pregnant or plan to be pregnant within 1 year; Any condition that may interfere with any study procedures, such as dementia, immobility, alcohol use, etc; Participating in any other clinical trial of an investigational drug or device that has not met its primary endpoint.