Effect of External Counter Pulsation on Coronary Artery Disease (ECP-CAD)

CAD is the leading cause of non-tumor mortality in most countries, ECP is a non-invasive method which consists of three sets of pneumatic cuffs attached to each of the patient's legs at the calf and lower and upper thigh. The inflation of the cuffs is triggered by a computer, and timing of the inflation is based on the R wave of the electrocardiogram. The ECP therapist adjusts the inflation and deflation timing to provide optimal blood movement per a finger plethysmogram waveform reading. This produces a retrograde flow of blood in the aorta resulting in a diastolic augmentation of blood flow and also an increase in venous return, which leads to an improved coronary perfusion pressure during diastole. Cumulative evidences demonstrate that ECP can improve life quality and release refractory angina which is not optimally controlled despite optimal medical management and coronary revascularization in patients with CAD, though the previous multi-center control trial (PROBE-EECP) had been designed, no result about the effect of ECP on the prognosis of CAD has been reported. Thus, this study is designed to enroll 380 participants with stable CAD after evaluation of frequency of angina pectoris, heart function, biomarkers of arteriosclerosis, exercise tolerance and endothelial function, participants will be randomized into ECP intervention group or control group. All participants receive Guideline-driven standard medical treatment, ECP will be carried out with a standard protocol which involves 35 one-hour sessions (5 days a week) for continuous 7 weeks. Up to the end of ECP intervention, CCE will be follow up to 1 year, meanwhile, items as above will be retested for comparison.