Among the most powerful technical improvements in coronary artery bypass graft (CABG) surgery has been the grafting of the left internal thoracic artery (ITA), instead of the saphenous vein (which doesn't stay open as long), to the left anterior descending coronary artery (LAD). In fact, use of ITA grafting has become a marker of quality CABG surgery. Doctors have been reluctant to use this approach in CABG surgery for the elderly due to their elevated surgical risks and shorter life expectancy. However, a new study demonstrating improved survival of elderly patients with use of ITA grafting may prompt them to reconsider this option.
In the study, which was supported in part by the Agency for Healthcare Research and Quality (HS10403), T. Bruce Ferguson, Jr., M.D., of the LSU Health Sciences Center and the Society of Thoracic Surgeons, and colleagues used data from a national cardiac database of over 500,000 patients who underwent non-emergency CABG surgery between 1996 and 1999. They analyzed the use of and complications associated with ITA grafting. Only 77 percent of patients aged 75 to 84 years received an ITA graft compared with nearly 94 percent of those aged 55 or younger. Yet this elderly ITA group had 27 percent less risk of dying within 30 days than a matched elderly non-ITA group.
In addition, the elderly ITA group did not have significantly higher likelihood of reoperation, stroke, and renal failure. Deep sternal infections were higher among the ITA versus non-ITA group, but the incidence was small (0.66 vs. 0.52 percent). When patients were divided into five groups based on their preoperative risk scores, mortality rates for those receiving an ITA were lower than the rates for those not receiving an ITA in each of the five predicted risk groups. However, the acute survival benefits of an ITA graft appeared to diminish in those aged 85 years or older. The impact of ITA use on long-term mortality among the elderly remains unclear, according to Dr. Ferguson.
See "Internal thoracic artery grafting in the elderly patient undergoing coronary artery bypass grafting: Room for process improvement?" by Dr. Ferguson, Laura P. Coombs, Ph.D., and Eric D. Peterson, M.D., M.P.H., in the May 2002 Journal of Thoracic and Cardiovascular Surgery 123(5), pp. 869-880.