Searching for the Second-Best Coronary Artery Bypass Graft

Abstract

Virtually all cardiac surgeons and their referring cardiologists know that the most effective and reliable coronary artery bypass conduit is the pedicled internal thoracic (mammary) artery (LITA) when placed to the left anterior descending artery coronary artery (LAD). This first choice of bypass graft conduits is based on convincing evidence of improved survival in patients with critical LAD disease in whom an LITA graft has been placed.1,2 The importance of an LITA graft when bypassing the LAD is so well accepted that it is now used as a quality indicator in the assessment of the performance of cardiac surgery programs in coronary artery bypass graft surgery (CABG).3 Article p 684 Unfortunately, how best to construct bypass grafts to other diseased coronary arteries in CABG patients, the vast majority of whom have multivessel disease and require several grafts, is not nearly as clearly understood. What is known is that the widely used saphenous vein graft has a significant and progressive failure rate; the probability of having a well-functioning vein graft 10 years after CABG is ≈60%.4 Because the remarkably durable LITA graft is so reliable and the saphenous vein graft so prone to progressive atherosclerosis-like deterioration, it has been most surgeons’ hope that “arterial” conduits might be the answer to improving graft durability and the effectiveness of CABG surgery. The Radial Artery Patency Study (RAPS) Investigators, surgeons from 12 Canadian hospitals and 1 New Zealand hospital, have addressed the question of whether an arterial graft, in this case the radial artery, will outperform the saphenous vein as a bypass conduit. In a previous report on this same well-designed randomized trial, Desai and colleagues5 demonstrated that radial artery grafts have lower rates of angiographically defined graft occlusion at a 1-year follow-up compared with saphenous vein grafts. In the …