To evaluate the influence of Salvianolate injection on myocardial microcirculation perfusion in subjects with STEMI who underwent primary PCI

This is a prospective, randomized, double-blind and controlled study.536 subjects of STEMI who underwent primary PCI within the first 12 hours will be enrolled.all patients were assigned to receive 300mg of asprin and ≥300mg of clopidogrel as loading dose,and following 100mg and 75mg once daily respectively.Patients were assigned to receive Salvianolate injection or 0.9% sodium chloride injection in catherter room setting,and following similar medicine once daily respectively for 7 days.Myocardial circulation perfusion will be checked with mmediate coronary angiography parameters,ECG,echocardiographic，CK-MB.The major adverse cardiovascular events will be observed.

Inclusion Criteria:

1. Informed consent must be obtained prior to any study procedure.
2. Age>18 years.
3. Subjects of STEMI who underwent primary PCI within the first 12 hours.

Exclusion Criteria:

1. Allergic to Salvianolate injection
2. Mechanical complications
3. History of severe renal or hepatic insufficiency
4. Pregnant or breastfeeding women
5. Pool compliance,greater risks result from the study