Reverse Remodeling of the Mitral Valve Complex After Radiofrequency Catheter Ablation for Atrial Fibrillation

Background: Mitral regurgitation is frequently complicated with atrial fibrillation without apparent organic changes in the leaflet, which occasionally improves after successful radiofrequency catheter ablation. We aimed to evaluate a possible geometric effect of radiofrequency catheter ablation on the mitral valve apparatus. Methods: Forty-three consecutive patients who underwent successful catheter ablation for persistent atrial fibrillation (maintaining sinus rhythm for 6 months after their procedure) were examined by serial real-time 3-dimensional transesophageal echocardiography before and 6 months after catheter ablation. Mitral valve complex geometry was measured using dedicated software for 3-dimensional transesophageal echocardiography. Results: Mitral valve apparatus showed significant reverse remodeling along with left atrial reverse remodeling 6 months after successful catheter ablation (50.5 [39.2–61.0] versus 36.4 [28.9–43.1] mL/m 2 ; P <0.001). The degree of mitral regurgitation decreased in a majority of patients (mitral regurgitation jet area; 1.83 [0.78–3.09] versus 0.77 [0.36–1.47] cm 2 ; P <0.001). Annular area significantly decreased (5.32±0.91 versus 4.73±0.76 cm 2 /m 2 ; P <0.001) in both anterior-posterior and medial-lateral directions. Mitral annular contraction significantly recovered after maintaining sinus rhythm for 6 months (7.51 [4.82–9.62]% versus 9.71 [6.27–13.85]%; P =0.008). There were no significant changes in tenting volume or tenting height (0.46 [0.27–0.89] versus 0.51 [0.32–0.72] mL/m 2 , P =0.744; 2.34 [1.75–3.48] versus 2.76 [1.99–3.08] mm/m 2 , P =0.717). The leaflet surface area also significantly decreased after catheter ablation (5.74 [5.01–6.33] versus 5.19 [4.63–5.64] cm 2 /m 2 ; P <0.001). Conclusions: Maintaining sinus rhythm after successful catheter ablation promotes reverse remodeling in the mitral valve apparatus and improves so-called atrial functional mitral regurgitation. The positive geometric effect of catheter ablation would be expected to be a possible contributor to better outcomes in patients with atrial fibrillation, in addition to the postprocedural freedom from rhythm disturbance.