Association between stress hyperglycaemia and in‐hospital cardiac events after coronary artery bypass grafting in patients without diabetes: A retrospective observational study of 5450 patients

AIMS: To investigate the impact of stress hyperglycaemia (SH) on in-hospital adverse cardiac events after coronary artery bypass grafting (CABG) in patients without diabetes. MATERIALS AND METHODS: In total, 5450 patients without diabetes who underwent CABG were analysed. SH was defined as any two instances in which the random blood glucose level was >7.8 mmol/L after CABG in the intensive care unit (ICU). The primary outcome was major adverse cardiac events (MACEs), including in-hospital mortality, acute myocardial infarction, stroke and acute renal failure. Secondary outcomes included surgical site infection (SSI) and length of ICU stay. RESULTS: Patients with SH had higher rates of MACEs (5.7% vs. 2.3%, p < .0001) and higher SSI (3.3% vs. 1.4%, p = .0003) and longer ICU stays (2.6 ± 2.0 vs. 1.3 ± 1.3 days, p < .0001) than those without SH. Furthermore, SH was associated with a higher risk of MACEs [odds ratio (OR): 2.32, 95% confidence interval (CI): 1.38-3.90], SSI (OR: 2.21, 95% CI: 1.20-3.95) and longer ICU stay (OR: 12.27, 95% CI: 9.41-16.92) after adjusting for confounders. Subgroup analysis showed that patients with SH >10 mmol/L or SH that occurred in the ICU and lasted more than 48 h had increased risks of postoperative complications (p < .05). CONCLUSIONS: SH was significantly associated with an increased risk of MACEs, SSI and longer ICU stay after CABG in patients without diabetes. In addition, SH >10 mmol/L or that occurred in the ICU and lasted more than 48 h increased the risk of adverse outcomes.