The role of newly diagnosed diabetes mellitus for poor in-hospital prognosis of coronary artery bypass grafting

Background : The management of coronary artery disease in patients with type 2 diabetes (T2DM) who need myocardial revascularization is a great challenge. Aims : To study the role of newly diagnosed T2DM in the development of in-hospital adverse outcomes after coronary artery surgery (CABG). Methods : 708 consecutive patients underwent CABG were included. All patients without history of T2DM and with border fasting hyperglycemia underwent an oral glucose tolerance test. Results : The screening allowed to diagnose T2DM in 8.9% and prediabetes in 10.4% of the study population. The the number of patients with T2DM increased from 15.2% to 24.1%, and with prediabetes from 3.0% to 13.4%. The total number of patients with carbohydrate metabolism disorders increased from 18.2% to 37.5%. The trend towards higher rate of in-hospital complications after CABG was defined among patients with newly diagnosed and previously diagnosed T2DM. The regression analysis demonstrated the presence of the relationships between the previously diagnosed T2DM and the total number of significant complications (odds ratio (OR) 1.350, 95% confidence interval (CI): 1.057–1.723, p=0.020) and prolonged in-hospital stay (OR 1.609, 95%CI 1.202–2.155, p=0.001). The significance of these relationships increased with the addition of newly diagnosed T2DM to the regression model (for in-hospital complications: OR 1.731, 95% CI 1.131–2.626, p=0.012; for prolonged in-hospital stay: OR 2.229, 95%CI 1.412–3.519, p<0.001). Moreover, additional associations between T2DM and the risk of developing multiple organ dysfunction (OR 2.911, 95% CI 1.072–7.901, p=0.039), urgent lower extremity surgery (OR 1.638, 95%CI 1.009–15.213, p=0.020) and the need for extracorporeal correction of hemostasis (OR 3.472, 95%CI 1.042–11.556, p=0.044) have been defined. Importantly, the presence of these associations would not have been identified without including newly diagnosed DM in the regression model. Conclusion : The newly diagnosed T2DM affects the prognosis of CABG as well as the previously diagnosed T2DM. The obtained results suggest the importance of active preoperative T2DM screening.