Clinical comparison between patients with saphenous vein and internal mammary artery as a coronary graft

From January, 1971, through May, 1978, the records of 1,239 patients who had comparable patterns of coronary artery bypasses were retrieved for study from the Ochsner computerized data bank. Seven hundred twenty-six patients had saphenous vein grafts (SVG) alone and 513 patients had internal mammary artery (IMA) grafts alone or in combination with SVG. Patients with IMA grafts had significantly improved survival over patients with SVGs, but after exclusion of biasing subgroups the improved survival was not reliably different (p = 0.1684). The percentages of patients who had unrelieved angina after operation were similar (5.0% versus 4.8%); the rates of nonfatal myocardial infarction and of postoperative congestive heart failure were also similar. When the recently done SVG bypasses were compared to those done before mid-1975, we found that unrelieved angina rates and nonfatal myocardial infarction rates were significantly improved in the recent group. We conclude that use of the SVG is indicated in some clinical situations and use of the IMA graft in others. Therefore, cardiovascular surgeons should be proficient in using both grafts.