To investigate the efficacy and safety of Tongxinluo in patients with microvascular angina pectoris. Long-term follow-up of 1 to 5 years will be performed to evaluate the effect of Tongxinluo on long-term adverse cardiovascular events in patients with coronary microvascular disease.

Inclusion Criteria:

1. Repeated chest pain attacks with typical exertional angina pectoris or resting angina pectoris attacks;
2. Coronary normal or stenosis < 20%;
3. Ischemic depression in ST segment during resting or exercise;
4. Blood flow reserve (CFR) of the anterior descending coronary artery < 2.0;
5. Subjects or their guardians agreed to participate in this study.

Exclusion Criteria:

1. Previous myocardial infarction or PCI or CABG treatment;
2. A history of heart failure or LVEF < 50%;
3. Severe arrhythmia;
4. Myocarditis, Pericardium Disease, Valvular Disease, or Cardiomyopathy;
5. A history of stroke within half a year;
6. Diabetes difficult to control;
7. Refractory hypertension or hypertension accompanied by left ventricular wall thickness > 12 mm;
8. Familial hypercholesterolemia;
9. Takayasu arteritis, Kawasaki disease or coronary artery malformation;
10. Pregnant or nursing, or having the intention to give birth within one year;
11. Hepatic or renal dysfunction;
12. Other diseases which may cause serious risks to patients;
13. Requiring warfarin anticoagulant therapy; Taking potassium channel opener, CCB, ACEI drugs or traditional Chinese medicines;
14. Allergic to contrast agents or blood products;
15. Patients who participated in clinical research of other drugs within 3 months before being selected.