Unilateral versus bilateral internal mammary revascularization. Survival and event-free performance

Abstract

Background: The influence of unilateral (UL) and bilateral (BL) mammary artery revascularization, within age groups < or = 60 years and > 60 years, on patient survival, ischemic-related events, and interventional management was studied in 1142 patients who had coronary artery bypass graft surgery between 1984 and 1992.

Methods and results: UL revascularization was performed in 765 (67%) and BL in 377 (33%) patients with supplemental vein grafts. The overall early and hospital mortality rate was 2.7%. For UL in the age group < or = 60 years, it was 1.1%; for BL < or = 60 years, 1.3% (P = NS); for UL > 60 years, 4.3%; and for BL > 60 years, 2.8% (P = NS). Twenty-five preoperative patient characteristics representing demographics, extent of disease, concomitant disease, ventricular dysfunction, previous surgery, and status did not differentiate the patient groups (P = NS). Patient survival at 5 years was not different: 94% for UL < or = 60 years, 95% for BL < or = 60 years, 91% for UL > 60 years, and 86% for BL > 60 years (P = NS). The freedom from ischemic-related events was not different at 5 years (P = NS). The freedom from recurrent angina was 78% for UL < or = 60 years, 88% for BL < or = 60 years, 82% for UL > 60 years, and 83% for BL > 60 years (P = NS). The myocardial infarction freedom was 98% for UL < or = 60 years, 96% for BL < or = 60 years, 99% for UL > 60 years, and 97% for BL > 60 years (P = NS). The freedom from sudden unexpected death and cardiac death did not differentiate the groups (P = NS). The freedom from angioplasty and reoperation did not differentiate the groups (P = NS). The freedom from all ischemic-related and interventional events was 76% for UL < or = 60 years, 84% for BL < or = 60 years, 81% for UL > 60 years, and 79% for BL > 60 years (P = NS). A trend exists for less angina pectoris in the bilateral population < or = 60 years, which reflects in the trend in the freedom from overall events.

Conclusions: UL and BL mammary artery revascularizations have the same early mortality regardless of age but do not reveal any advantage for BL revascularization at 5 to 7 years.