Glycemic control and risk factors for in‐hospital mortality and vascular complications after coronary artery bypass grafting in patients with and without preexisting diabetes

BACKGROUND: The purpose of this study was to investigate risk factors of in‐hospital mortality and vascular complications after coronary artery bypass grafting (CABG), particularly the effect of different glycemic control levels on outcomes in patients with and without previous evidence of diabetes. METHODS: A total of 8682 patients with and without previous diabetes undergoing CABG were categorized into strict, moderate, and liberal glucose control groups according to their mean blood glucose control level <7.8 mmol/L, 7.8 to 10.0 mmol/L, and ≥10.0 mmoL/L after in‐hospital CABG. RESULTS: The patients with previous diabetes had higher rates of in‐hospital mortality (1.3% vs 0.4%, P < .001) and major complications (7.0% vs 4.8%, P < .001) than those without diabetes. Current diabetes was significantly associated with a higher risk of in‐hospital mortality (odds ratio [OR] = 3.14, 95% confidence interval [CI] 1.87‐5.27) and major complications (OR = 1.49, 95% CI 1.24‐1.80), and smoking and higher low‐density lipoprotein cholesterol (LDL‐C) levels showed similar results. Among patients with previous diabetes, strict glucose control was significantly associated with an increased risk of in‐hospital mortality (OR = 8.32, 95% CI 3.95‐17.51) compared with moderate glucose control. Nevertheless, among non‐previous diabetic patients with stress hyperglycemia, strict glucose control led to a lower risk of major complications (OR = 0.71, 95% CI 0.52‐0.98). CONCLUSIONS: Diabetes status, smoking, and LDL‐C levels were modifiable risk factors of both in‐hospital mortality and major complications after CABG. Strict glucose control was associated with an increased risk of in‐hospital mortality among patients with diabetes, whereas it reduced the risk of major complications among non‐previous diabetic patients.