Influence of the Internal-Mammary-Artery Graft on 10-Year Survival and Other Cardiac Events

TLDR

We compared 2306 patients who received an internal‑mammary‑artery graft (alone or with saphenous veins) to 3625 patients who had only saphenous‑vein bypass grafts. At 10 years, survival was higher with internal‑mammary‑artery grafts (93.4% vs 88.0% for one‑vessel disease, 90.0% vs 79.5% for two‑vessel disease, 82.6% vs 71.0% for three‑vessel disease) and multivariate analysis showed a 1.61‑fold higher mortality risk, 1.41‑fold higher late myocardial infarction risk, 1.25‑fold higher cardiac‑event hospitalization risk, 2.00‑fold higher reoperation risk, and 1.27‑fold higher overall late cardiac‑event risk in the vein‑only group. Published in N Engl J Med 1986; 314:1–6.

Abstract

We compared patients who received an internal-mammary-artery graft to the anterior descending coronary artery alone or combined with one or more saphenous-vein grafts (n = 2306) with patients who had only saphenous-vein bypass grafts (n = 3625). The 10-year actuarial survival rate among the group receiving the internal-mammary-artery graft, as compared with the group who received the vein grafts (exclusive of hospital deaths), was 93.4 percent versus 88.0 percent (P = 0.05) for those with one-vessel disease; 90.0 percent versus 79.5 percent (P<0.0001) for those with two-vessel disease; and 82.6 percent versus 71.0 percent (P<0.0001) for those with three-vessel disease. After an adjustment for demographic and clinical differences by Cox multivariate analysis, we found that patients who had only vein grafts had a 1.61 times greater risk of death throughout the 10 years, as compared with those who received an internal-mammary-artery graft. In addition, patients who received only vein grafts had 1.41 times the risk of late myocardial infarction (P<0.0001), 1.25 times the risk of hospitalization for cardiac events (P<0.0001), 2.00 times the risk of cardiac reoperation (P<0.0001), and 1.27 times the risk of all late cardiac events (P<0.0001), as compared with patients who received internal-mammary-artery grafts. Internal-mammary-artery grafting for lesions of the anterior descending coronary artery is preferable whenever indicated and technically feasible. (N Engl J Med 1986; 314:1–6.)