Bivalirudin is widely used as an anticoagulant to reduce the risk of bleeding in PCI perioperative period. Additionally, 15.7%-32.7% patients have diabetes mellitus who undergo percutaneous coronary interventions (PCI), so bivalirudin was used to anticoagulate in these patients to evaluate its safety and efficacy.

Bivalirudin is a specific reversible thrombin direct inhibitor and the function of thrombin activity site can be recovered through hydrolyzing bivalirudin by thrombin. Therefore, bivalirudin is widely used as an anticoagulant during percutaneous coronary intervention (PCI) for coronary heart disease, and 15.7%-32.7% patients have diabetes mellitus who undergo percutaneous coronary interventions (PCI). At the same time, elderly patients have higher risk of bleeding whose age over 65, so bivalirudin can reduce the risk of bleeding and the incidence of net adverse clinical events for the elderly patients whose age over 65 with diabetes mellitus in PCI perioperative period.

Inclusion Criteria:

1. ≥ 65 years, with diabetes mellitus.
2. Patients who undergo selective PCI therapy.
3. Patients who agree to participate in this clinical trial and sign informed consent prior to surgery.

Exclusion Criteria:

1. Patients with acute coronary syndrome undergoing primary PCI.
2. Combined with other diseases, the life expectancy of patients don't exceed 1 year.
3. Patients with active bleeding.
4. Bleeding in the gastrointestinal or urogenital tract in the past 6 weeks.
5. Combined with high risk of postoperative hemorrhage, such as active gastric ulcer, active ulcerative colitis, etc.
6. Patients who have undergone major surgery in the last 1 month.
7. A history of intracranial bleeding or structural abnormalities, such as cerebral aneurysms.
8. Patients with cardiogenic shock, or suspected myocarditis, infective endocarditis.
9. Patients who received regular heparin therapy within 6 hours or low molecular weight heparin therapy within 8 hours, or other factors that the researchers believe may influence the outcome of the trial.
10. Patients with severe uncontrolled hypertension.
11. Patients with active hepatitis, HIV and other infectious diseases.
12. Patients with contraindications of bivalirudin and heparin.
13. Other researchers considered the patients are unfit to participate in this study.