CABG is still the treatment of choice for ischemic heart disease. However, restenosis or occlusion may occur to graft vessels, leading to postoperative myocardial ischemia and subsequent clinical events. Long-term angiographic follow-up demonstrated that vein graft restenosis and occlusion are common among those receiving CABG, with a vein graft patency of less than 50% at 15 years postoperatively. Besides, it is found that graft occlusion may occur as early as 3 months after the surgery. It is, therefore, a major priority to improve the short-term postoperative vein graft patency so as to achieve better prognosis for patients.