To investigate the efficacy and safety of Compound Danshen Dripping Pill in patients with diabetic microvascular angina pectoris. Long-term follow-up of 1 year will be performed to evaluate the effect of Compound Danshen Dripping Pill on coronary flow reserve and adverse cardiovascular events in patients with coronary microvascular disease.

Inclusion Criteria:

History of type 2 diabetes ≧5 years; Repeated chest pain attacks with typical exertional angina pectoris or resting angina pectoris attacks; Coronary normal or stenosis <50%; Ischemic depression in ST segment during resting or exercise; Coronary flow reserve (CFR) of the anterior descending coronary artery < 2.0, or CFR ≧2.0 but acetylcholine activation test is positive; Subjects or their guardians agreed to participate in this study.

Exclusion Criteria:

Previous myocardial infarction or PCI or CABG treatment; Severe arrhythmia; Refractory hypertension or hypertension accompanied by left ventricular wall thickness > 12 mm; Familial hypercholesterolemia; Takayasu arteritis, Kawasaki disease or coronary artery malformation; Pregnant or nursing, or having the intention to give birth within one year; Hepatic or renal dysfunction; Allergic to contrast agents or traditional Chinese medicines; Patients who participated in clinical research of other drugs within 3 months before being selected.

It might damage the privacy of patients.