a. Stable coronary heart disease with objective evidence of atherosclerosis, either coronary angiography shows ≥50% stenosis of at least one of the coronary main stems or first-level branches, or typical exertional angina pectoris with positive stress tests(ECG stress test, echocardiograph stress test, or stress radionuclide myocardial imaging). b Diagnosed of myocardial infarction at least 3 months before recruitment. c.Coronary revascularization(PCI or CABG) at least 3 months before recruitment.