Does diabetes mellitus increase immediate surgical risk in octogenarian patients submitted to coronary artery bypass graft surgery?

Introduction: Diabetes is a well known risk factor for early and late adverse outcomes in patients undergoing coronary artery bypass graft surgery (CABG); however, few studies have investigated the impact of this risk factor in the group of older patients, especially octogenarians. Objectives: To compare in-hospital mortality and morbidity of diabetic and nondiabetic patients aged >= 80 years submitted to CABG. Methods: A total of 140 consecutive cases were studied, of whom 37 (26.4%) were diabetics, in a retrospective cross-sectional study, that included all patients aged >= 80 years submitted to isolated/associated CABG. The patients' mean age was 82.5 +/- 2.2 years and 55.7% were males. Results: The hospital mortality rate did not significantly differ in multivariate analysis: 16.2% diabetic x 13.6% nondiabetic (P = 0.554), as well as morbidity: 43.2% x 37.9%, respectively (P = 0.533). Regarding to operative morbidity, the occurrence of stroke was significantly higher in diabetic patients in the univariate analysis (10.8% x 1.9%, P = 0.042). In multivariate analysis, however, the incidence of stroke was not associated with the presence of diabetes (P = 0.085), but it was associated with atrial fibrillation (P = 0.044). There was no significant difference related to other complications. Conclusion: In this small consecutive retrospectively analyzed series, there was no significant increase in hospital mortality and morbidity related to diabetes for CABG in octogenarian patients. The impact of the results of this study is limited by the sample size and might be confirmed by future randomized clinical trials.