At present, the two treatment strategies of opening non infarct related arteries (non IRA) simultaneously or by stages after emergency percutaneous coronary intervention (PCI) in patients with acute ST segment elevation myocardial infarction (STEMI) complicated with multi vessel disease (MVD) are still controversial. In our previous retrospective analysis, there was no significant difference between complete revascularization (CR) and staged CR at Anzhen Hospital in the cases of cardiac death, reinfarction, stroke, proportion of revascularization and hospitalization rate of heart failure.

The literature reports on the benefits of two CR strategies of opening non IRA simultaneously or by stages after IRA treatment in STEMI patients are inconsistent. This study intends to enroll 426 cases and divide into two groups to verify whether the occurrence of major cardiovascular adverse events (all-cause death, nonfatal myocardial infarction, ischemia driven revascularization and heart failure) in one year in immediately open non-IRA after successful emergency PCI of infarct related arteries in STEMI patients with MVD group is not inferior to staged (within 45 days) CR group. It can accumulate more evidence-based medical basis for the selection of better treatment schemes, so as to formulate optimized treatment schemes for clinic. To study when to open meaningful non IRA in acute STEMI complicated with MVD is of great guiding significance for CR after acute myocardial infarction. At the same time, it has important social significance and economic value for delaying or preventing cardiovascular events.

Inclusion Criteria:

1. Onset of the spontaneous acute STEMI (24 hours).
2. The anatomical structure of coronary artery is suitable for complete revascularization by PCI.
3. It is suitable for PCI through radial artery or femoral artery.
4. Be able to fully identify Infarct-related artery（IRA）.
5. In addition to IRA, in the vessels of lumen diameter is 2.25mm or more, but less than 4.5mm. there is at least one non IRA's stenosis more than 70% observed in both planes, or 50% ~ 69% stenosis and fractional flow reserve (FFR) or Quantitative Flow Ratio (QFR) measured value is 0.80 or less.
6. After IRA revascularization the thrombolysis in myocardial infarction (TIMI) blood flow is in grade 3.
7. The hemodynamics of patients after IRA revascularization is stable, that is, systolic blood pressure ≥ 90mmHg, or blood pressure ≥ 90mmHg after catecholamines, and there is no clinical manifestation of hypoperfusion.
8. Patient who has signed informed consent

Exclusion Criteria:

1. Cardiogenic shock which means a group of clinical syndromes leading to cardiac dysfunction caused by various reasons, which meet the following criteria: A: continuous hypotension, systolic blood pressure < 90mmHg or mean arterial pressure decreased from baseline ≥ 30mmhg, more than 30min; B: cardiac index < 1.8l/min/m2, pulmonary congestion or elevated left ventricular filling pressure; c: Signs of organ perfusion damage (at least one): changes in mental state, wet and cold skin, oliguria, and increased serum lactic acid level.
2. The duration of cardiopulmonary resuscitation is more than 10 minutes.
3. Emergency coronary artery bypass grafting (CABG) is needed.
4. Previous coronary-artery bypass grafting surgery.
5. Hybrid revascularization is planned.
6. Coronary dissection.
7. Stent thrombosis.
8. In stent restenosis, definition: A: target vessel diameter stenosis ≥ 50% at follow-up. b: The lumen loss at follow-up was larger than 50% of the net lumen gain after operation. c: The lumen diameter at follow-up and the minimum diameter loss measured immediately at stenting were 0.72 mm or more.
9. Acute myocardial infarction complicated with severe mechanical complications, defined as acute severe mitral regurgitation, ventricular septal perforation and cardiac free wall rupture / pericardial tamponade.
10. Severe renal failure (EGFR < 30ml / min) or dialysis treatment is required.
11. Chronic total occlusion of main coronary artery.
12. Complex bifurcation lesions requiring dual stent treatment.
13. Stenosis of Left main coronary artery≥ 50% or stenosis of left anterior descending coronary artery and circumflex coronary artery ≥ 70%.
14. Coronary, cerebrovascular or peripheral revascularization is planned.
15. Cardiac surgery or other surgical treatment is planned.
16. Contraindications to double antibody therapy [aspirin and P2Y12 inhibitor (clopidogrel or ticagrelor) for 3 months.
17. pregnant woman.
18. Patient who has participated in other clinical trials.
19. Life expectancy < 1 year.
20. Patient who is not suitable for inclusion in the study according to the operator's judgment.](streamdown:incomplete-link)