The effect of rhythm control for atrial fibrillation on coexisting secondary mitral valve regurgitation: Initial results from a large, real-world registry

M. Nies (Hamburg)¹, A. Fowé (Hamburg)², J. Obergassel (Hamburg)³, J. Rieß (Hamburg)¹, N. Schenker (Hamburg)⁴, S. Kany (Hamburg)¹, M. Lemoine (Hamburg)¹, F. Ouyang (Hamburg)¹, B. Reißmann (Hamburg)⁵, P. Kirchhof (Hamburg)⁶, A. Metzner (Hamburg)⁴, A. Rillig (Hamburg)⁴, D. Kalbacher (Hamburg)^5
1Universitäres Herz- und Gefäßzentrum Hamburg Klinik für Kardiologie Hamburg, Deutschland; ²Universitäres Herz- und Gefäßzentrum Klinik für Kardiologie Hamburg, Deutschland; ³Universitätsklinikum Hamburg-Eppendorf Klinik für Kardiologie Hamburg, Deutschland; ⁴Universitäres Herz- und Gefäßzentrum Hamburg Klinik für Kardiologie mit Schwerpunkt Elektrophysiologie Hamburg, Deutschland; ⁵Universitäres Herz- und Gefäßzentrum Hamburg Allgemeine und Interventionelle Kardiologie Hamburg, Deutschland; ⁶Universitäres Herz- und Gefäßzentrum Hamburg Klinik für Kardiologie Lübeck, Deutschland

Background: Atrial fibrillation (AF) and secondary mitral valve regurgitation (SMR) frequently coincide and reciprocally accelerate disease progression in a vicious cycle. Data on the effect of rhythm control on comorbid SMR are scarce.
Objective: To evaluate the effect of successful rhythm control of AF on the severity of clinically significant SMR.
Methods: Patients with AF presenting for catheter ablation were consecutively enrolled in the prospective TRUST-registry (NCT05521451) since March 2021. Cross-sectional follow-up was carried out from May 2024 to October 2025. Transthoracic echocardiography (TTE), 12-lead ECG, and NT-proBNP were assessed in all patients undergoing catheter ablation at baseline. All patients with at least moderate SMR in the baseline TTE and a follow-up TTE at ≥1 year or mitral valve intervention during follow-up were included in the analysis. Patients with primary MR or prior mitral valve interventions were excluded. Successful rhythm control was defined as sinus rhythm at follow-up.
Results: In total, 87 patients met the inclusion criteria (76 [IQR 67-81] years, 55/87 (63.2%) women). Of these, 66/87 (75.9%) presented in sinus rhythm at follow-up 2.2±1.0 years after ablation and were included in the analysis (57 with moderate, and 9 with severe SMR). Baseline parameters are displayed in Table 1. Improvement of MR ≥1 grade was observed in 46/66 (69.7%) patients (Figure). Three patients (4.5%) underwent transcutaneous or surgical mitral valve repair before follow-up and were considered to have had no improvement in MR severity. While left atrium (LA) size was similar at baseline, patients with improved SMR showed a significantly lower LA volume index as compared to non-responders at follow-up (34.5±9.2 vs. 46.7±15.5 ml/m²; p=0.04; Figure). Patients without improvement were significantly older (78 [IQR 76-82] vs. 72 [IQR 66-79] years; p=0.01) and had a higher CHA₂DS₂-VA Score (3 [IQR 2-4] vs. 2 [IQR 1-3]; p=0.03). No significant differences in diuretic therapy or heart failure medication were observed between the groups.
Conclusion: In patients with atrial fibrillation and at least moderate secondary mitral regurgitation, rhythm control via catheter ablation is associated with improved mitral valve function in more than two thirds of cases. Differences in LA dimensions may indicate favorable effects on atrial remodeling. Larger studies are needed to confirm these observations and to clarify the underlying mechanisms.