We prospectively study CAD patients [Canadian Cardiovascular Society (CCS) angina class II-IV], before and after ECPT , and compare them with age- and sex-matched controls. Peripheral blood CD34+ cells, EPCs (CD34/VEGFR2+ cells), EPC colony forming units (CFUs) and brachial artery endothelial function is assessed prior to and after ECPT. Percent improvement in endothelium-dependent brachial artery flow-mediated dilatation (%FMD) is assessed using high-resolution ultrasound.