Arterial grafts do not counteract target vessel occlusion.

Grafted, non-occluded coronary arteries might contribute substantially to the myocardial blood supply and serve as a basis for vascular collateralization which preserves the myocardium in the event of graft occlusion. Early studies indicated that grafting with saphenous vein, but not internal mammary arteries, accelerates coronary atherosclerosis. This has not been extensively studied for the radial artery, which like the internal mammary artery (IMA) is largely resistant to atherosclerosis. A differential effect of various grafts might facilitate identification of disease-modifying principles. Our surgical cohort represented an opportunity to analyse new native coronary occlusions by comparison with preoperative angiograms. One hundred and two patients underwent angiography 1.3-3.9 years after coronary artery bypass surgery, primarily in order to compare the patency of radial artery, IMA and saphenous vein grafts. Out of 290 stenotic, grafted vessels, 67 (23%) occluded during follow-up. Native occlusion occurred in 47% of the patients and correlated with serum-cholesterol. In a per target analysis, independent predictors of postoperative native occlusion were the right coronary artery territory, patent corresponding graft, the corresponding graft being an IMA and end-to-side anastomosis. Target vessel occlusion is similar with radial artery and saphenous vein grafts and proceeds rapidly even in the current era of secondary prophylaxis against atherosclerosis. Competitive graft flow appears to promote occlusion. Contrary to previous studies, we do not find vein grafts to be inferior to IMA grafts with respect to preservation of native vessel patency.