The use of a radial artery graft compared with a saphenous vein graft for coronary artery bypass grafting did not result in improved angiographic patency one year after the procedure, according to the study “Radial artery grafts vs saphenous vein grafts in coronary artery bypass surgery: A randomised trial” published on 12 January 2011 issue of the Journal of the American Medical Association (JAMA).
Coronary artery bypass grafting is one of the most common operations performed in the United States, with a database indicating that 163,048 patients had this type of surgery in 2008. The success of the surgery depends on the long-term patency of the arterial and venous grafts. Arterial grafts are thought to be better conduits than saphenous vein grafts for coronary artery bypass grafting based on experience with using the left internal mammary artery to bypass the left anterior descending coronary artery, according to background information in the article. The efficacy of the radial artery graft, which is easier to harvest than other arteries, is less clear.
Steven Goldman and colleagues from Southern Arizona VA Health Care System and the University of Arizona Sarver Heart Center, Tucson, compared one year angiographic patency of radial artery grafts vs. saphenous vein grafts in 757 participants (99% men) undergoing elective first time coronary artery bypass grafting. The randomised controlled trial was conducted from February 2003 to February 2009 at 11 Veterans Affairs medical centers. The left internal mammary artery was used to preferentially graft the left anterior descending coronary artery whenever possible; the best remaining recipient vessel was randomised to radial artery vs. saphenous vein graft. The primary outcome measured was angiographic graft patency at one year after coronary artery bypass grafting. Angiographic graft patency at one week after coronary artery bypass grafting, heart attack, stroke, repeat revascularisation and death were among the secondary results.
The analysis included 733 patients (366 in the radial artery group, 367 in the saphenous vein group). The researchers found that there was no significant difference in one year graft patency between radial artery (238/266; 89%) and saphenous vein grafts (239/269; 89%). Also, there was no significant difference in one week patency between patients who received radial artery grafts (285/288; 99%) vs. saphenous vein grafts (260/267; 97%), or in the other secondary outcomes. There was no difference in the number and types of adverse events, including serious adverse events.
“Although most clinicians assume that compared with vein grafts, arterial grafts have an improved patency rate, there are little multi-institutional prospective data on radial artery graft vs. saphenous vein graft patency,” the authors wrote.
Long-term patency is the important question to answer, therefore the researchers will continue with a 5-year angiographic follow up of these patients to define chronic graft patency in this population.
