Patients were eligible to be included in the study if they met any of the following criteria: 1) Coronary angiography (CA) or multi-slice CT coronary angiography (CTCA) suggestive of moderate to severe coronary artery stenosis. 2) Chest tightness, onset of shortness of breath, and poor exercise tolerance after receiving formal drug treatment (with or without stent or bypass graft). 3) Hospitalized more than 2 times within 1 year due to the aforementioned problems. 4) CCS angina grading higher than grade II, and NYHA functional classification of I-III. 5) More than 1 month after acute myocardial infarction (AMI) and more than 2 weeks after PCI surgery. The diagnosis and treatment in all the patients was in accordance with the related domestic and European guidelines developed in 2007