Impact of diabetes mellitus on outcomes in Japanese patients undergoing coronary artery bypass grafting

Background and purpose: There have been no large-scale studies on the impact of diabetes mellitus (DM) on outcomes in Japanese patients undergoing coronary artery bypass grafting (CABG). Methods and subjects: A multi-institutional retrospective cohort study was conducted in 14 Japanese centers. All adult patients who underwent isolated CABG from 2007 to 2008 were included (n=1522, mean age: 68.5 years). The definitions of DM were all patients admitted with diagnosis of DM and preoperative glycated hemoglobin (Hb) A1c >= 6.5%. Univariate and multivariate analyses were performed to identify the risk of morbidity and mortality. Results: There were 849 DM and 572 non-DM patients. Preoperative mean HbA1c were 7.1% in the DM group and 5.7% in the non-DM group (p < 0.0001). Preoperative, intraoperative, and 3-day average postoperative blood glucose (BG) were 146 mg/dl, 172 mg/dl, and 168 mg/dl in the DM group, and 103 mg/dl, 140 mg/dl, and 136 mg/dl in the non-DM group (all p < 0.0001). Although there were no significant differences in postoperative cardiovascular events, the incidence of infection was significantly higher in the DM group than in the non-DM group (9.2% vs 6.1%, p=0.036) on the univariate analysis. The all-cause death was also relatively higher in the DM group than in the non-DM group (2.1% vs 1.1%, p = 0.12), and this was likely related to infection. Conclusion: DM patients had worse perioperative BG control, higher incidence of infection, and higher mortality than non-DM patients. These results indicate that perioperative BG control guidelines should be standardized to obtain better surgical outcomes in Japanese DM patients. (C) 2012 Published by Elsevier Ltd on behalf of Japanese College of Cardiology.