Objectives: Patients with diabetes mellitus undergoing coronary-artery bypass grafting (CABG) have been repeatedly suggested to have worse clinical outcomes compared to patients without DM. The objective of this study was to evaluate the impact of diabetes mellitus on 1-year clinical outcomes after isolated CABG.
Methods: The European DuraGraft registry included 1130 patients (44.6%) with and 1402 (55.4%) patients without diabetes mellitus undergoing isolated CABG. Intra-operatively, all free venous and arterial grafts were treated with an endothelial damage inhibitor. Primary end-point in this analysis was the incidence of a major adverse cardiac event, a composite of all-cause death, repeat-revascularization or myocardial-infarction at 1-year post CABG. To balance between differences in baseline characteristics (n = 1,072 patients in each group) propensity score matching was used. Multivariable Cox proportional hazards regression was performed to identify independent predictors of major adverse cardiac events.
Results: Diabetic patients had a higher cardiovascular risk-profile and EuroScore II with overall more comorbidities. Patients were comparable in regard to surgical techniques and completeness of revascularization. At 1-year, diabetics had a higher major adverse cardiac event rate (7.9% vs 5.5%, hazard ratio (HR) 1.43 (95% CI 1.05-1.95), p = 0.02), driven by increased rates of death (5.6% vs 3.5%, HR 1.61 (95% CI 1.10-2.36), p = 0.01) and myocardial infarction (2.8% vs 1.4%, HR 1.99 (95% CI 1.12-3.53) p = 0.02). Following propensity matching, no statistically significant difference was found for major adverse cardiac events (7.1% vs 5.7%, HR 1.23 (95% CI 0.87-1.74) p = 0.23) or its components. Age, critical operative state, extracardiac arteriopathy, ejection-fraction ≤50% and left-main disease, but not diabetes mellitus were identified as independent predictors for major adverse cardiac events.
Conclusions: In this study, 1-year outcomes in diabetics undergoing isolated CABG was comparable to patients without diabetes mellitus.
