Background: The purpose of this study was to find the preoperative and intraoperative factors that affect vein graft patency.
Methods: A total of 3715 graft angiograms in 1607 patients were studied for recurrence of angina. The preoperative patient characteristics and intraoperative variables were prospectively collected from patients who had primary coronary artery bypass grafting during the period from 1977 to 1999. A total of 1339 (83%) patients were male, with a mean age of 59 years. The mean period from operation to reangiogram was 99 months. The saphenous vein was grafted to the left anterior descending artery in 557 (15%), to the diagonal artery in 669 (18%), to the obtuse marginal artery in 1300 (35%), to the right coronary artery in 409 (11%), and to the posterior descending artery in 780 (21%) cases. Graft failure was defined as >or=80% stenosis.
Results: During the course of the study, 2266 (61%) grafts were patent, and 1449 (39%) had failed. The patient variables that significantly reduced graft patency were a younger age (P <.001) and an ejection fraction <30% (P =.047). Operative variables associated with reduced graft patency were small coronary artery diameter (P <.001), large conduit diameter (P =.001), and the coronary artery grafted (lowest patency in the right coronary artery and maximum patency in the left anterior descending artery territory; P =.002). The interval from operation to repeat angiogram (P <.001, with 78% patent at 1 year, 78% at 5 years, 60% at 10 years, and 50% at 15 years) and the year in which the operation was performed (more recent operations had better patency; P <.001) significantly affected graft patency.
Conclusions: Saphenous vein graft patency improved over the course of the study. The best results were obtained in older patients with good left ventricular function. Large-caliber arteries on the left system, when grafted with a small-diameter vein, were associated with the best outcome.