Coronary atherosclerotic heart disease (CAD) has been considered the leading cause of death in both developed and developing countries. Coronary artery bypass grafting (CABG) is a major therapy of CAD in the world, mainly used for patients with left main disease, multi-vessel complex disease, stent implantation failure, heart failure and diabetes.

Studies have demonstrated that significant angiographic defects up to 12% of grafts, which was observed by immediate coronary angiography after CABG. Despite secondary prevention were performed in patients after CABG, the early failure rate at 1 year is higher, up to 15-20%, the 10-year patency rate of internal mammary artery graft is 85%, and the 10-year patency rate of saphenous vein graft is only 61%, and 10-20% of patients require revascularization within 10 years after CABG.

Patients with failed grafts usually have a higher surgical risk and the morality of repeat CABG is 2-4 times higher than primary surgery. Because of the poor clinical prognosis of patients undergoing repeat CABG, PCI is the preferred treatment strategy for revascularization in patients with previous CABG. In patients with previous CABG, approximately 75% of PCI target vessels are native vessels.

Compared with native vessel PCI, bypass graft PCI has a higher rate of short- and long-term major adverse events, including more than double the in-hospital mortality rate. Some studies support the above view，but others denied. Therefore, the primary study mainly to explore the effect of native vessel PCI or graft PCI on the prognosis of patients with previous CABG.

Inclusion Criteria:

• Patients received first percutaneous coronary intervention in native arteries or in bypass grafts after coronary artery bypass grafting

Exclusion Criteria:

• Patients who missed follow-up data were excluded

Coronary artery disease patients received first percutaneous coronary intervention in native arteries or in bypass grafts after coronary artery bypass grafting