A multicenter randomized double-blind placebo parallel control design was used in this study.60 subjects eligible for inclusion will be randomly assigned to either a low-dose (0.25ug/kg) medium-dose (0.5ug/kg) high-dose (2.0ug/kg) experimental drug group or a control group (placebo) at a ratio of 1:1:1:1.After randomization, subjects received the experimental drug or placebo once a day, intravenously, on day 2 to 7, 12 hours and 4 hours after PCI.Ninety days after PCI were observed.

Subjects underwent cardiovascular magnetic resonance imaging (CMR) on the 90th day after PCI, which was used to evaluate the myocardial salvage index myocardial infarction area, microvascular occlusion area, left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), and left ventricular end-diastolic volume (LVEDV).Echocardiography was performed on the 5th and the 90th day after PCI to evaluate the left indoor diameter (LV) and left atrial diameter (LA) of LVEF. Physical examination routine blood coagulation function was performed on the 30th and 90th day after PCI in the screening period (pre-screening results were acceptable);Electrocardiogram (ECG) was performed on the 30th and the 90th day after PCI on the 2nd day after the first administration;During the screening period (results before screening are acceptable), vital signs should be measured from day 1 to day 7 after PCI (during each dose, vital signs should be measured twice on day 7, including before and after administration), on day 30 and day 90;Blood biochemical examinations were performed from day 2 to day 4, day 7, day 30, and day 90 after PCI before the first administration;Creatine kinase isoenzyme (CK-MB) hypersensitive troponin I(HS-CTNI) or troponin I(cTnI) and amino-terminal B-type natriuretic peptide precursor (NT-probNP) or B-type natriuretic peptide (BNP) were detected on day 2, day 3, day 4 and day 7 after PCI before the first administration.Tumor markers were detected and immunogenicity blood samples were collected 30 days after PCI before the first administration.Routine urinalysis was performed 90 days after PCI before the first administration;Adverse drug events and cardiovascular events were continuously recorded during the trial.