Consequences of a New Onset Postoperative Atrial Fibrillation on Mortality Following Coronary Artery Bypass Grafting

Approximately 20% to 40% of individuals having coronary artery bypass grafting (CABG) develop new-onset postoperative atrial fibrillation (POAF). Objective: This study examined the impact of POAF on both early and late mortality following CABG. Methods: This research study was conducted at the Choudhury Pervaiz Elahi Institute of Cardiology in Wazirabad, Pakistan. The study was conducted retrospectively and involved analyzing data from patients who underwent isolated CABG (Coronary Artery Bypass Grafting) surgery between December 2022 and December 2023. The study included 110 participants who had preoperative sinus rhythm and no previous history of atrial fibrillation. To minimize the impact of confounding factors, propensity score matching was used. Both early and late mortality were analyzed using logistic and Cox regression. Results: The study had a mean follow-up time of 18±3.3 months, and 26 patients (23.6%) reported postoperative atrial fibrillation (POAF). The early death rates were 2.2% in all patients, 3.2% in the POAF group, and 1.7% in the non-POAF group (p = 0.001). However, a multivariate analysis did not show POAF as an independent risk factor for early death (p = 0.172). The logistic regression analysis also did not indicate that POAF was a risk factor for early death after quintiles of the propensity score were considered (OR, 1.46; 95% CI, 0.97 to 2.21; p = 0.152). Interestingly, postoperative AF remained an independent risk factor for early death in our multivariate analysis, with an HR of 1.37 (95% CI, 1.05 to 1.84; p = 0.035). Furthermore, the HR of POAF for overall mortality, adjusted for quintiles of the propensity score of POAF, was 1.38 (95% CI, 1.10 to 1.75; p = 0.008). Conclusions: POAF independently predicts overall and late mortality following independent CABG, whereas it does not predict early mortality.