Post-ablation left atrial function impacts long-term recurrence of atrial fibrillation after ablation

Left atrial (LA) function can help predict various cardiovascular events. Catheter ablation for atrial fibrillation (AF) modifies baseline LA function through the maintenance of sinus rhythm and myocardial injury. We investigated the impact of post-ablation LA function on recurrence of AF after ablation and identified the predictors of reduced post-ablation LA function. A total of 616 patients who underwent AF ablation (paroxysmal, N = 310; non-paroxysmal, N = 306) were retrospectively examined with cardiac computed tomography at baseline and 3 months after the final ablation procedure. Post-ablation LA emptying fraction (LAEFpost) was calculated. We evaluated the association between LAEFpost and recurrence of AF after the final ablation procedure. Further, we assessed the predictors of reduced LAEFpost. The recurrence rate of AF was 72.7% after the final ablation procedure [median follow-up 48 months (48.0, 48.0), total number of ablation sessions: 1.4 ± 0.7]. Multivariate analysis revealed that LAEFpost was associated with the recurrence of AF (hazard ratio/10% increase: 0.62, 95% confidence interval: 0.51–0.75, P < 0.0001). LAEFpost had a mild predictive power for recurrence of AF (c-statistics: 0.670, optimal cutoff: 26.36%, P < 0.0001). The recurrence-free proportion among patients with reduced LAEFpost (< 26.36%, N = 100) and those with preserved LAEFpost (≥ 26.36%, N = 516) was 40% and 79%, respectively (P < 0.0001). The predictors of reduced LAEFpost were low pre-ablation LAEF, high pre-ablation LA volume, low body mass index (BMI), and female sex. Further, reduced LAEFpost was associated with the total number of ablation sessions and extra-pulmonary vein LA ablation. In conclusion, reduced LAEFpost was associated with recurrence of AF after ablation. Advanced LA remodeling, low BMI, and female sex could predict reduced LAEFpost. Although additional ablation was associated with reduced LAEFpost, it remains unclear whether reduced LAEFpost resulted from the additional ablation. Reduced LAEFpost might help stratify patients with ablation-refractory AF.