Radial artery bypass grafts are associated with increased occurrence of angiographically severe stenosis and occlusion compared with left internal mammary artery and saphenous vein grafts

Abstract

Conclusion: Patients who have undergone previous coronary artery bypass grafting who have signs and symptoms of myocardial ischemia have lower patency rates of radial artery grafts compared to internal mammary artery and saphenous vein grafts. Summary: The authors reviewed coronary angiography procedures at their institution from February 1996 to October 2001. Patients with radial artery bypass grafts were selected. Angiographic outcomes were divided into 3 groups: occluded, severe disease (>70% stenosis), and patent (<70% stenosis). Multivariable analysis was used to determine predictors of severe disease or occlusion. There were 310 patients with radial artery grafts. Mean follow-up after coronary artery bypass grafting was 565 ± 511 days. Radial artery grafts had a patency rate of 51.3%. This was significantly lower than left internal mammary artery grafts (90.3%; P < .0001) or saphenous vein grafts (84.0%; P = .0016). Revision rate in radial artery grafts was 33.7%, compared with 4.8% for left internal mammary artery grafts (P < .0001). Radial artery grafts had a severe stenosis rate of 15.1%, compared with 5.9% for saphenous vein grafts (P = .0002) and 4.8% for left internal mammary artery grafts (P = <.0001). Radial artery graft patency was worse in women than in men (38.9% vs 56.1%; P = .025). The most powerful multivariable predictor of severe stenosis or occlusion was a radial artery graft (χ2 = 28.82; P = <.0001). The presence of a radial artery graft led to 58 patients requiring subsequent percutaneous interventions and 26 patients requiring repeat coronary artery bypass grafting. Comment: These results are in significant contrast to the widespread belief that radial artery grafts have a high rate of patency in coronary artery bypass grafting. The data suggest that improvements in harvesting techniques of radial artery grafting and the postoperative administration of calcium channel blockers delayed rather than prevented the previously documented poor outcome of radial artery grafts in the coronary circulation.