Bilateral Internal Mammary Artery Grafting Enhances Survival in Diabetic Patients: A 30-Year Follow-Up of Propensity Score-Matched Cohorts
Background—The prevalence of diabetes is increasing at an unprecedented rate, affecting nearly 8% of the population. Previous studies have demonstrated a potential benefit for surgical over interventional revascularization in this group of patients. Similarly, studies have shown the superiority of bilateral internal mammary artery (BIMA) grafting over single internal mammary artery (SIMA) grafting in select populations. However, concerns regarding sternal wound infection (SWI) have discouraged the use of BIMA grafting in diabetics. Therefore, we studied the long-term results of BIMA vs. SIMA grafting in a large population of diabetic patients in which BIMA grafting was broadly applied.
Methods and Results—Between February 1972 and May 1994, 1107 consecutive diabetic patients underwent coronary artery bypass grafting (CABG) with either SIMA (n=646) or BIMA (n=461) grafting. Optimal matching using propensity score-matching was used to create matched SIMA (n=414) and BIMA (n=414) cohorts. Cross-sectional follow-up (6 weeks to 30.1 years, mean 8.9 years) determined long-term survival. There was no difference in operative mortality (OM) sternal wound infection (SWI) or total complications between matched SIMA and BIMA groups (OM: 10/414; 2.4% vs. 13/414: 3.1%, P=0.279; SWI 7/414; 1.7% vs. 13/414; 3.1%; P=0.179); total complications 71/414, 17.1% vs. 71/414, 17.1%, P=1.000). Late survival was significantly enhanced with the use of BIMA grafting (median survival SIMA 9.8 years vs. BIMA 13.1 years; P=0.001). Use of BIMA was found to be associated with late survival on Cox regression (P=0.003).
Conclusions—BIMA, compared with SIMA, grafting in propensity score-matched patients provides diabetics with enhanced survival without any increase in perioperative morbidity or mortality.
- Received May 9, 2012.
- Accepted October 22, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited