Ablation of atrial fibrillation during coronary artery bypass grafting: Late outcomes in a Medicare population

Background: This study compares outcomes of patients with preoperative atrial fibrillation undergoing coronary artery bypass grafting (CABG) with or without concomitant atrial fibrillation ablation in a nationally representative Medicare cohort. Objectives: This study examined early and late outcomes in CABG patients with a preoperative history of atrial fibrillation to determine the correlation between surgical atrial fibrillation ablation to mortality and stroke or systemic embolization. Methods: In the Medicare-linked Society of Thoracic Surgeons database, 361,138 patients underwent isolated CABG from 2006 to 2013; 34,600 (9.6%) had preoperative atrial fibrillation; 10,541 (30.5%) were treated with surgical ablation (ablation group), and 23,059 were not (no ablation group). Propensity score matching was performed using a hierarchical mixed model. Long-term survival was summarized using Kaplan-Meier curves and Cox regression models with robust variance estimation. The stroke or systemic embolization incidence was modeled using the FineGray model. Median follow-up was 4 years. Results: Long-term mortality in propensity score-matched CABG patients (mean age 74 years; Society of Thoracic Surgeons risk score, 2.25) receiving ablation versus no ablation was similar (log-rank P = .30). Stroke or systemic embolization occurred in 2.2% versus 2.1% at 30 days and 9.9% versus 12.0% at 5 years (Gray P = .0091). Landmark analysis from 2 to 5 years showed lower mortality (hazard ratio, 0.89; 95% confidence interval 0.82-0.97; P = .0358) and lower risk of stroke or systemic embolization (hazard ratio, 0.73; 95% confidence interval, 0.61-0.87; P = .0006) in the ablation group. Conclusions: Concomitant ablation in CABG patients with preoperative atrial fibrillation is associated with lower stroke or systemic embolization and mortality in patients who survive more than 2 years.

Automated summary

This study found that among patients undergoing CABG, those who received atrial fibrillation ablation had lower mortality and rates of stroke or systemic embolization compared to those who did not receive ablation. Additionally, patients in the ablation group had lower long-term mortality and risk of stroke or systemic embolization from 2 to 5 years.