Bivalirudin is recomended by guidelines during primary PCI procedure for patients with STEMI. However, there is a large number of STEMI patients who missed the primary PCI. So the investigators aim to study the efficiency and safety of bivalirudin as the anticoagulation therapy during late PCI.

Antithrombotic therapy is essential to prevent adverse ischemic events, especially stent thrombosis and reinfarction during and after primary percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). Bivalirudin is emerging as an alternative for heparin during PCI procedure1.

Bivalirudin (BIV) a synthetic, bivalent, 20-amino acid direct thrombin inhibitor, was found to have the advantages of inhibiting fibrin-bound thrombin, a predictable effect of anticoagulation, and a short half-life of approximately 30 minutes in humans with normal renal function. BIV has been introduced in percutaneous coronary interventions (PCIs) especially for patients with ACS. Compared with heparin, series clinical trials indicated that BIV was not inferior to UFH as a procedural anticoagulant and there was no increased bleeding.

In the real world, there are as many as 47.1% patients with STEMI can not get early reperfusion therapy. Huge number of patients missed the best time window for PCI. For these patients, the usual PCI procedure are usually performed 1-2 weeks after attack, which is called late PCI.

For patients with STEMI, Bivalirudin is recomended by guidelines in ESC during PCI procedure. However, the evidences (ACUITY，HORIZONS-AMI，EUROMAX, EAT-PPCI，BRIGHT, VALIDATE-SWEDEHEART) supporting the guideline nearly all comes from primary PCI for STEMI, which means there has no clinical trials focus on late PCI for patients with STEMI yet.

Clinically, late PCI, defined as the time to open an infarct-related artery (IRA) from symptoms onset > 7 days (when the myocardial condition is considered stable), is practiced commonly for these late presenters. Whether late PCI is adequately beneficial is controversial. Currently, heparin is applied during late PCI as the anticoagulation therapy, it is still unknown of the efficiency and safety for bivalirudin as the anticoagulation therapy during late PCI.

So in this RCTs, the investigators aim to study the efficiency and safety of bivalirudin as the anticoagulation therapy during late PCI.

Inclusion Criteria:

1. Patients aged over 18 years.
2. Patients with ST-segment elevation MI (STEMI) undergoing late PCI 24 hours to 2 weeks after symptom onset. STEMI was defined as ST-segment elevation ≥0.1 mV in ≥2 contiguous leads or documented newly developed left bundle branch block.
3. Patients with develop Q-waves at presentation and with clear culprit vessel confirmed by angiography or other clinical evidences.
4. No any other anticoagulation therapy 12 hours before late PCI.

Exclusion Criteria:

- STEMI patients undergoing primary PCI in 24 hours after symptom attack; patient unwilling or unable to provide written informed consent. thrombolytic therapy administered before randomization; any condition making PCI unsuitable or that might interfere with study adherence;