UNILATERAL VERSUS BILATERAL INTERNAL MAMMARY REVASCULARIZATION - SURVIVAL AND EVENT-FREE PERFORMANCE

Background The influence of unilateral (UL) and bilateral (BL) mammary artery revascularization, within age groups <less than or equal to >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 less than or equal to 60 years, it was 1.1%; for BL <less than or equal to >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 <less than or equal to >60 years, 95% for BL less than or equal to 60 years, 91% for UL >60 years, and 56% 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 <less than or equal to >60 years, 88% for BL less than or equal to 60 years, 82% for UL >60 years, and 83% for BL >60 years (P=NS). The myocardial infarction freedom was 98% for UL <less than or equal to >60 years, 96% for BL less than or equal to 60 years, 99% for UI, >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 <less than or equal to >60 years, 84% for BL <less than or equal to >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 <less than or equal to >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.