To determine the therapeutic effects of Tongxinluo Capsules as compared with placebo in the treatment of patients with acute ST-elevation myocardial infarction (STEMI): (1) Clinical efficacy and safety at 30 days: the incidence of composite endpoints comprising major adverse cardiovascular and cerebrovascular events (MACCE, including cardiovascular death, myocardial re-infarction, emergency coronary revascularization and cerebral stroke), severe complications (including cardiogenic shock, heart failure, mechanical complications and malignant arrhythmias), and major bleeding (BARC grade III and V); (2) Clinical efficacy and safety at 1 year: the incidence of composite endpoints comprising MACCE, hospitalization due to heart failure, in-stent thrombosis, and major bleeding (BARC grade III and V), as well as all-cause mortality; (3) the effects in promoting myocardial reperfusion, reducing incidence of myocardial no-reflow, protecting ischemic myocardium, minimizing infarction size, and improving left ventricular systolic function.

Inclusion Criteria:

1. Age>18 years;
2. Within 24 hours of infarctional chest pain onset;
3. ECG shows ST-segment elevation ≥0.2mV in more than 2 adjacent leads, or new left bundle branch block (LBBB);
4. Voluntary participation in the study with consent forms signed.

Exclusion Criteria:

1. Critically illness due to STEMI;
2. Long-term (>20 min) cardio-pulmonary resuscitation (CPR);
3. Suspected aortic dissection or acute pulmonary embolism;
4. Explicit mechanical complications, including interventricular septum perforation, rupture of papillary muscles and chordae tendineae, or on-going or ruptured left ventricular free walls.
5. Serious cardiogenic shock and do not responding to hypertensive agents;
6. Uncontrolled acute left heart failure or pulmonary edema;
7. Malignant arrhythmias uncontrolled by anti-arrhythmia agents;
8. Bleeding history of cerebral vessels, gastrointestinal tract, respiratory tract, urinary tract or other organs within 1 month;
9. Presence of active hemorrhage at any part of the body (including menstruation);
10. Known hemorrhagic constitution or serious hemostasis and blood coagulation disorders;
11. Current usage of anticoagulants (such as Warfarin or new anticoagulants);
12. . Serious hepatorenal dysfunction [ATL≥5 ULN (upper limit of normal), Cr>134μmol/L (2mg%) or eGFR<45ml/min/1.73m2];
13. Serious chronic obstructive pulmonary disease (COPD) or respiratory failure;
14. . Severe infection:
15. . Very weak or frailty;
16. . Neuropsychiatric system diseases;
17. . Malignancies;
18. . Other pathophysiological conditions with expected survival time <1 year;
19. Allergy to the ingredients of this investigational drug;
20. Women who are in pregnancy or nursery;
21. Participation in clinical study of other traditional Chinese medicine (TCM);
22. Unsuitability to participate in this study due to other diseases.