Factors Influencing 1-year Patency of Coronary Artery Saphenous Vein Grafts

To evaluate the possible influence of a series of clinical angiographic and surgical variables on the l-year patency of saphenous vein (SV) coronary graft, data collected prospectively in a multicenter randomized clinical trial were analyzed. The study group included 349 patients - 847 SV distal anastomoses -who underwent angiography at a median time of 374 days after surgery. By logistic binomial regression analysis, age, sex, smoking habits, hypertension, high cholesterol, previous myocardial infarction, and angina were not found to be significant factors leading to graft occlusion. Among the angiographic and surgical variables, the following were retained as predictive of higher occlusion risk. (1) vessel diameter (. 1.5 mm versus > 1.5 mm, odds ratio (OR) =2.46); (2) the location of the grafted vessel, namely, the right coronary artery versus the left anterior descending (OR=2.15); and (3) the wall motion of the vessel-dependent myocardial region (altered versus normal: OR=2.12). The presence of two or three risk factors multiplied the occlusion risk up to 11-fold. The study suggests that vessel diameter, wall motion of the vessel-dependent myocardial region, and location of the grafted vessel are the main determinants of SV coronary graft patency during the first postoperative year. Knowledge of these artery-specific factors may provide a basis for estimating the risk of graft occlusion, thereby modifying surgical strategy and postoperative surveillance.