The purpose of this study is to evaluate whether perioperative use of Shenfu Injection could reduce myocardial injury (enzymatic infarct size and infarct volume according to cardiac magnetic resonance imaging) in patients with STEMI after primary PCI

Inclusion Criteria:

1. Age ≥18 and <75 years;
2. First-time acute anterior STEMI;
3. The time from onset of ischemic symptom to the time of initial PCI balloon inflation ≤6 hours;
4. >0.1 mV ST segment elevation in at least two contiguous precordial leads according to electrocardiogram;
5. Scheduled for primary PCI;
6. The presence of left anterior descending branch (LAD) occlusion in proximal or middle segment with pre-PCI TIMI flow 0 or 1 according to baseline coronary angiogram;
7. Written informed consent.

Exclusion Criteria:

1. Hypertrophic cardiomyopathy, aortic valve stenosis and/or regurgitation, pericarditis, or myocarditis;
2. Cardiogenic shock, severe ventricular arrhythmia, serious heart failure (Killip class III and above) or mechanical complications;
3. Patients after cardiopulmonary resuscitation (CPR) (including cardioversion);
4. Patients who have already received thrombolytic therapy;
5. Prior myocardial infarction or coronary artery bypass surgery;
6. Known serious hepatic, renal, blood, respiratory, or neuropsychiatric diseases;
7. Malignant tumor, lymphoma, HIV-positive, or hepatitis;
8. Uncontrolled hypertension (systolic BP >160 mm Hg or a diastolic BP >100 mmHg on at least two consecutive readings);
9. Patients with active bleeding, major surgery or trauma within 3 months and cerebrovascular accident within 6 months;
10. History of anemia (hemoglobin<90g/L) or thrombocytopenia (thrombocyte<90×109/L);
11. Multi-vessel disease with non-culprit vessel intervention;
12. Breastfeeding, pregnant, or potentially fertile women;
13. Patients who have known to be allergic to Shenfu Injection or its components or patients with serious adverse effect;
14. Patients with potential contraindication to CMR;
15. Participation in other clinical trial in recent 3 months;
16. Patients who cannot complete this trial or comply with the protocol.