Long-term patency of saphenous vein and left internal mammary artery grafts after coronary artery bypass surgery: results from a Department of Veterans Affairs Cooperative Study.

OBJECTIVES: This study defined long-term patency of saphenous vein grafts (SVG) and internal mammary artery (IMA) grafts. BACKGROUND: This VA Cooperative Studies Trial defined 10-year SVG patency in 1,074 patients and left IMA patency in 457 patients undergoing coronary artery bypass grafting (CABG). METHODS: Patients underwent cardiac catheterizations at 1 week and 1, 3, 6, and 10 years after CABG. RESULTS: Patency at 10 years was 61% for SVGs compared with 85% for IMA grafts (p < 0.001). If a SVG or IMA graft was patent at 1 week, that graft had a 68% and 88% chance, respectively, of being patent at 10 years. The SVG patency to the left anterior descending artery (LAD) (69%) was better (p < 0.001) than to the right coronary artery (56%), or circumflex (58%). Recipient vessel size was a significant predictor of graft patency, in vessels >2.0 mm in diameter SVG patency was 88% versus 55% in vessels 2.0 mm in diameter.

Comparison of postoperative comlications between saphenous vein and IMA grafts to left anterior descending coronary artery.

Considerable controversy exists regarding relative morbidity associated with the saphenous vein graft (SVG) and internal mammary artery (IMA) graft in patients undergoing myocardial revascularization. As a part of the cooperative study on use of antiplatelet drugs for graft patency, operative and postoperative data were prospectively collected on 1,150 patients who underwent either SVG (n = 656) or IMA anastomosis (n = 494) to the left anterior descending coronary artery. There were no differences in baseline characteristics of patients, distribution of randomization among treatment groups, and total number of distal anastomoses performed between the two groups. The aortic cross-clamp time, cardiopulmonary bypass duration, operative time, and chest tube drainage were greater (p = 0.0001) in the patients with IMA grafts compared with SVG. However, there was no difference in the operative mortality rate, the amount or blood and blood products received, the reoperation rate for control of postoperative bleeding, and incidence of wound complications between the two groups. The early and 1-year patency rates for the IMA were slightly but not significantly better than the SVG patency rates (92.8% versus 90.1% for 1-year patency; p = 0.309). In conclusion, use of IMA is associated with a longer operative time as well as increased postoperative bleeding compared with the SVG. It, however, does not increase operative mortality or postoperative morbidity.