Increased glucose variability is associated with atrial fibrillation after coronary artery bypass

Area of Science:

• Cardiology
• Endocrinology
• Metabolic Syndrome

Background:

• Elevated preoperative hemoglobin A1c (HbA1c) predicts poor outcomes in coronary artery bypass grafting (CABG).
• The impact of postoperative glucose variability (GV) on outcomes after CABG remains unclear.
• This study investigates the association between short-term postoperative GV and atrial fibrillation risk.

Purpose of the Study:

• To determine if short-term postoperative glucose variability (GV) is an independent predictor of postoperative atrial fibrillation (POAF) after isolated CABG.
• To assess the relationship between mean glucose levels in the first 24 hours post-CABG and POAF.
• To evaluate the predictive value of preoperative HbA1c for POAF in the context of postoperative glucose control.

Main Methods:

• Retrospective analysis of 2073 patients undergoing isolated CABG (January 2012-March 2018).
• Measurement of postoperative GV within the first 24 hours using standard deviation, coefficient of variation, and mean amplitude of glycemic excursions.
• Multivariate logistic regression models were employed to identify independent predictors of POAF.

Main Results:

• Postoperative atrial fibrillation (POAF) occurred in 446 patients (21.5%).
• Increased 24-hour GV was significantly associated with a higher risk of POAF (OR=1.16, P<0.01).
• Elevated 24-hour mean glucose also independently predicted POAF (OR=1.14, P<0.01), with a 16% and 14% increased risk for every 10% GV and 10 mg/dL mean glucose increase, respectively.

Conclusions:

• Increased 24-hour glucose variability and mean glucose are significant predictors of atrial fibrillation following CABG.
• Preoperative HbA1c did not predict POAF when postoperative glucose metrics were considered.
• Further research is warranted to explore strict glucose control strategies to mitigate adverse events post-CABG.