Study of Efficacy of External CounterPulsation on Reducing the Prevalence of Vein Graft Failure and Improving Cardiac Function for Postoperative Coronary Artery Bypass Grafting Patients

Coronary artery disease (CAD) is prevalent worldwide and the leading cause of mortality of citizens. Coronary Artery Bypass Grafting (CABG)is one of the major revascularization procedures for multi-vessel disease nowadays. However vein graft failures (VGF) are known to occur frequently following CABG surgery . It is estimated that VGF developed in 25% patients in half a year postoperatively, and up to 50% vein grafts would result in occlusion in ten years postoperatively. Surgical success depends on the continued patency of grafts, and VGF has been associated with worse outcomes in CABG patients. Thus prevention of VGF following CABG is an active area of scientific inquiry. External counter pulsation (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.ECP has been elucidated that it may release angina symptoms and improve the prognosis of CAD, however, it remained unknown that weather EECP can reduce VGF rates following CABG surgery. The aim of this study is to evaluate the effect of ECP on heart function of CABG patients and VGF rates.

To address this investigation, patients underwent CABG with at least one vein graft are enrolled and randomize them into control or ECP group, the ECP intervention will be carried out with a standard protocol which involves 35 one-hour sessions (5 days a week) for continuous 7 weeks, and the follow-up will last for 2 years. The primary endpoints are the 2-year major composite cardiovascular events (MACEs,) and 2-year vein graft patency rate determined by coronary CT angiography, secondary endpoints include scoring of angina pectoris, heart function by echocardiography, biomarkers of arteriosclerosis and endothelial function.