Predictors of new-onset atrial fibrillation in elderly patients with coronary artery disease after coronary artery bypass graft

Objective To identify the factors associated with the development of postoperative atrial fibrillation (POAF) after coronary artery bypass graft (CABG) in elderly patients with coronary artery disease (CAD). Methods A total of 81 patients with CAD who underwent CABG were enrolled in the study. Patients were divided into two groups: Group 1, without postoperative atrial fibrillation (59 patients, 74.6% men, mean age 65.8 ± 4.0 years); Group 2, with early new-onset atrial fibrillation after CABG (22 patients, 90.9% men, mean age 67.7 ± 5.4 years). Interleukin (IL)-6, IL-8, IL-10, C-reactive protein (CRP), fibrinogen, superoxide dismutase (SOD), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and troponin I were studied. Results During the observation period, atrial fibrillation occurred in 27.2% cases, an average of 4.9 ± 3.8 days after surgery. In group 2, the left atrium (LA) dimension was larger than in group 1 (43.9 ± 3.4 mm vs. 37.6 ± 3.9 mm, P P = 0.04), IL-8 (11.9 ± 6.0 pg/mL vs. 7.7 ± 5.4 pg/mL, P = 0.01) and SOD (2462.0 ± 2029.3 units/g vs. 1515.0 ± 1292.9 units/g, P = 0.04) compared with group without POAF. The multivariate analysis showed that the odds ratio (OR) for POAF development in patients with left atrium more than 39 mm was 2.1 95% confidence interval (CI): 1.2?3.8, P = 0.0004, IL-6 levels more than 65.18 pg/mL—1.4 (95% CI: 1.1?2.7, P = 0.009), IL-8 levels more than 9.67 pg/mL—1.2 (95% CI: 1.1?3.7, P = 0.009), SOD more than 2948 units/g—1.1 (95% CI: 1.01?2.9, P = 0.04). Conclusions In our study, the independent predictors of postoperative atrial fibrillation after CABG in elderly patients were left atrium dimension and the increased postoperative concentration of IL-6, IL-8 and superoxide dismutase.