Type 2 diabetes mellitus first diagnosed before surgery affects the immediate prognosis for coronary artery bypass grafting
Authors: Bezdenezhnykh N , Sumin AN , Bezdenezhnykh AV , Osokina AV , Gruzdeva OV , Belik EV , Barbarash OL 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Federal State Budgetary Institution “Research Institute for Complex Issues of Cardiovascular Diseases”

Purpose
To study the preoperative status and assess the rate of in-hospital complications in patients with newly diagnosed type 2 diabetes mellitus (DM) undergoing coronary artery bypass grafting compared to patients with previously diagnosed DM and normoglycemia.
Materials and Methods. 708 consecutive patients who underwent coronary artery bypass grafting (CABG) between 2011 to 2012 at the Research Institute for Complex Issues of Cardiovascular Diseases were included in the study. All patients without positive history of diabetes underwent an oral glucose tolerance test (ОGTT). The lab findings were interpreted in accordance with the recommended diagnostic criteria for diabetes and other glycemic disorders.
Results. DM screening before coronary artery bypass grafting allowed to diagnose type 2 diabetes in 8.9% (n = 63) and prediabetes in 10.4% (n = 74) of the study population. The preoperative screening increased the number of patients with DM from 15.2% (n = 108) to 24.1% (n = 171), and with prediabetes from 3.0% (n = 21) to 13.4% (n = 95). The total number of patients with carbohydrate metabolism disorders increased from 18.2% (n = 129) to 37.5% (n = 266). The study groups did not differ in the rate of in-hospital complications due to a relatively low number of occurred events. However, a trend towards higher rate of in-hospital complications after CABG was defined among patients with newly diagnosed and previously diagnosed DM. The regression analysis demonstrated the presence of the relationships between the previously diagnosed DM2 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: 1.202-2.1555, p = 0.001). The significance of the mentioned above relationships increased with the addition of newly diagnosed diabetes to the regression model as a probable predictor (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 &lt;0.001). Moreover, additional associations between DM 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 diabetes mellitus affects the prognosis of CABG as well as the previously diagnosed DM. The obtained results suggest the importance of active preoperative DM screening.