Coronary Angiography after Coronary artery Bypass Grafting

Choi, Jin Ho; Park, Kay Hyun; Jun, Tae Gook; Lee, Young Tak; Park, Pyo Won; Chae, Hurn; Lee, Jong Tae

Abstract

BACKGROUND: There have been many reports of coronary angiographic findings aft er coronay bypass grafting,most of which are focused on the graft patency rate of the bypass conduits. However,postoperative angiography can provide numerous informations other than patency rates that are useful for establishing operative strategy. MATERIAL AND METHOD: We studied 73 patients in whom coronary angiography was done after more than 1 month of CABG.Mean interval from the operation to coronary angiography was 10.6 months and the reasons for coronary angiography follow up were residual or recurrent angina in 54 patients, abnormalities on myocardial perfusion scan or echocardiography in 13 patients,and for simple follow up in 6 patients. RESULT: Overall graft patency rate was 80.9% (internal thoracic artery 100%,saphenous vein 75.0%) in patients of simple follow up and 61.6% (internal thoracic artery 81.1%,saphenous vein 55.3%) in patients with ischemia. Progression of native coronary arterial disease proximal to the grafting site was found in 50 patients(68.5%). Among 201 coronary arterial branches that had not been completely occluded preoperatively, ninty five branches(47.3%)revealed progression of diameter stenosis by more than 20%on the follow up study. Among them,64 branches(31.8%)progressed to total occlusion.The incidence of disease progression was highter in the coronary arteries with patent grafts (57.5%)than in those with occluded grafts(36.3%)(p < 0.05). Comparing internal thoracic artery graft with saphenous vein graft, internal thoracic artery was superior to saphenous vein,not only in terms of patency(83.3% vs 56.6%), but also in terms of result of later percutaneous intervention success rate(100% vs 62%,p < 0.05).
CONCLUSION
Due to the considerable incidence of progression of native coronary artery stenosis in the early postoperative periods, bypass grafting of a vessel with borderline stenosis,especially with vein graft,must be done prudently. And it was confirmed again that revascularization of left anterior descending artery is most important and that internal thoracic artery was superior to saphenous vein.