Calcium-channel antagonists and nitrates in coronary artery bypass patients receiving radial artery grafts

OBJECTIVE: To review the literature assessing the role of vasodilators for the prevention of vasospasm leading to graft failure in patients receiving the radial artery (RA) as a conduit in coronary artery bypass grafting (CABG). DATA SOURCE: A MEDLINE search (January 1966-May 2000) was performed using calcium-channel antagonists, nitrates, radial artery, and coronary artery bypass as key words. English-language articles were identified, and the references of these articles were used to further identify pertinent articles. DATA SYNTHESIS: RAs can be used as conduits in CABG. It has been suggested that failure of these grafts may be due to vasospasm, leading to occlusion observed angiographically. Calcium-channel antagonists and nitrates have been proposed as a means of preventing vasospasm and subsequent graft failure. CONCLUSIONS: Currently published data on the use of calcium-channel antagonist or nitrate therapy as prophylaxis against vasospasm in patients receiving RA grafts are inconclusive. Systematic evaluations of currently available pharmacologic agents are needed to guide clinical practice in this area.