A new biomarker to predict atrial fibrillation and its adverse events after coronary artery bypass surgery: red blood cell distribution volume.

Objective: Recent studies suggest that increased red blood cell distribution width may be associated with increased risk of atrial fibrillation. This study aimed to evaluate the relationship between pre-operative and postoperative erythrocyte distribution volume, postoperative atrial fibrillation and related adverse events in patients undergoing isolated coronary artery bypass surgery.

Methods: A total of 790 patients (611 males, mean age 58.3 ± 6.2 years) in pre-operative sinus rhythm, who underwent isolated coronary artery bypass grafting with cardiopulmonary bypass at the same centre and by the same surgical team between January 2015 and December 2021, were enrolled retrospectively. Two groups were created, group 1 (n = 183) and group 2 (n = 607), with regard to the occurrence of atrial fibrillation in the early postoperative period or not, respectively. Clinical and demographic data, biochemical and complete blood count parameters, and intra-operative and postoperative data of the patients were recorded. Univariate and subsequent multivariate logistic regression analysis was done to determine significant clinical factors and independent predictors of postoperative atrial fibrillation.

Results: Among the patients, 182 (23.2%) developed atrial fibrillation during the 72 hours postoperatively. Pre-operative and postoperative first-, third- and seventh-day red blood cell distribution volume (p = 0.0001), C-reactive protein (p = 0.0001) and erythrocyte sedimentation rate (p = 0.0001) were significantly increased in group 1. Multivariate logistic regression analysis showed elevated pre-operative and postoperative first-, thirdand seventh-day red blood cell distribution volume, erythrocyte sedimentation rate and C-reactive protein as independent predictors of early postoperative atrial fibrillation.

Conclusions: Pre-operative and postoperative red blood cell distribution volume was found to be an independent predictor of atrial fibrillation and associated adverse events in the early postoperative period of isolated coronary artery bypass grafting.