Inclusion Criteria:  Age: 18 or over and less than 75 years old; ECG: ≥2 mm ST-segment elevation in 2 contiguous precordial leads or ≥1 mm ST-segment elevation in 2 contiguous extremity leads; Patents with STEMI with symptom onset between 24 and 48 hours before randomization; Signed informed consent form prior to trial participation.  Exclusion Criteria:  Patents with STEMI with symptom onset <24h or >48h or uncertain time onset. Prior administration of thrombolytic therapy or attempted PCI before randomization; Presence of indications for primary PCI, such as persistent chest pain, cardiogenic shock, life-threatening arrhythmias or cardiac arrest, severe acute heart failure, and mechanical complications; Coagulopathy, active peptic ulcer, history of cerebral or subarachnoid hemorrhage, stroke within 6 months, other contraindications for antiplatelet or anticoagulant therapy; Known intolerance to antiplatelet (e.g. aspirin, clopidogrel, ticagrelor) and anticoagulant therapy (e.g. heparin, bivalirudin); Presence of contraindications for CMR; Congenital heart disease or severe valvular disease; eGFR <30 ml/min/1.73 m2; History of malignant tumors; Combined with other diseases and life expectancy ≤12 months; Pregnancy; Inclusion in another clinical trial; Inability to provide informed consent or not available for follow-up judged by investigator.