# Active Detection of Glucose Metabolism Disorders Prior to Coronary Artery Bypass Grafting: Associations with In-Hospital Postoperative Complications

## TL;DR

Screening for glucose metabolism disorders before heart surgery reveals high rates of diabetes and prediabetes, which are linked to more postoperative complications.

## Contribution

This study demonstrates the value of active preoperative glucose screening in identifying undiagnosed diabetes and its strong association with postoperative complications.

## Key findings

- Screening increased diagnosed diabetes from 20.9% to 27.8% and prediabetes from 2.7% to 31.7%.
- Patients with diabetes or prediabetes had significantly higher risks of heart failure, organ failure, and wound complications.
- Adjusting for age and gender, glucose metabolism disorders remained significant predictors of postoperative complications.

## Abstract

Background/Objectives: Patients with coronary artery disease undergoing coronary artery bypass grafting (CABG) have a high prevalence of type 2 diabetes mellitus (T2DM) and prediabetes. Glucose metabolism disorders (GMDs) are often asymptomatic and remain undetected, but untreated they can have adverse effects. To evaluate the possibilities of active screening in identifying T2DM and prediabetes before CABG and to assess the impact of GMD on the incidence of postoperative complications. Methods: This study included 1021 patients who underwent CABG in 2016–2018 at the department of cardiovascular surgery, whose glycemic status was determined. All patients had their glycated hemoglobin (HbA1c) levels measured; those without a previous diagnosis of diabetes underwent an oral glucose tolerance test. The frequency of newly diagnosed diabetes and prediabetes was evaluated. Postoperative complication rates were analyzed among patient groups with various types of GMDs and normal blood glucose levels. Results: Screening before CABG increased the number of patients with established type 2 diabetes from 20.9 to 27.8% and the number of people with prediabetes from 2.7% to 31.7%. When analyzing hospital complications, patients with type 2 diabetes compared to patients with normoglycemia were significantly more likely to develop heart failure (p = 0.010), multiple organ failure (p = 0.002), require extracorporeal homeostasis correction (p = 0.011), and wound dehiscence (p = 0.004). Nine patients (0.9%) died following CABG without being discharged from the hospital, with 90% of these deaths occurring in patients with GMDs. Any GMD (diabetes or prediabetes) was associated with an increased incidence of postoperative heart failure (OR 1.259; p = 0.011), rhythm disturbances (OR 1.236; p = 0.010), major cardiovascular complications and/or heart failure (OR 1.193; p = 0.039), and all cardiovascular complications (OR 1.455; p = 0.002). In the presence of any GMD, the risk of multiple organ failure increased by 2.5 times (OR 2.506; p = 0.014), extracorporeal correction of homeostasis increased by 1.8 times (OR 1.821; p = 0.034), and diastasis of the wound edges increased by 1.3 times (OR 1.266; p = 0.005). It is important that, when adjusting for gender and age, the effect of GMD on the described complications remained significant. Conclusions: Active preoperative detection established an extremely high prevalence of GMD in patients with multivessel coronary artery disease (59.5%). T2DM and prediabetes are significant predictors of postoperative complications of coronary artery bypass grafting.