Introduction: The safety and effectiveness of catheter ablation in patients with atrial fibrillation (AF) who underwent mechanical mitral valve replacement (MVR) have been reported. However, the impacts of different types of mitral valves on the safety and effectiveness of catheter ablation in patients with AF who underwent MVR have not been elucidated. Methods and results: From 2015 to 2021, 17,496 patients underwent catheter ablation of AF for the first time in Beijing Anzhen Hospital were screened. The inclusion criteria were (1) aged 18 years or older; (2) diagnosed with AF; (3) history of mitral valve replacement. The exclusion criteria were a history of catheter ablation, surgical maze procedure, left atrial appendage closure or resection. A total of 68 patients were enrolled in the study. The patients were divided into two groups: the bioprosthetic MVR group (n=12) and the mechanical MVR group(n=58). The size of the left atrial was larger (49.5mm vs. 46.0mm, p<0.05), the thickness of the left interventricular septum was larger (11.0mm vs. 10.0mm, p<0.05), and the mitral ring area was smaller (2.3mm2 vs. 2.6mm2, p<0.05) for the bioprosthetic MVR group than the mechanical MVR group. During 23.4 (6.1, 36.5) months of follow-up, the incidence of the endpoint events was not significantly different between the two groups (33.3% vs. 30.4%, log-rank p=0.48). There were 2 cases (3.4%) of pseudoaneurysm and 1 case of acute cerebral infarction in the mechanical MVR group. No complication was observed in the bioprosthetic MVR group. No significant clinical bleeding events were observed in the bioprosthetic group while eight patients in the mechanical MVR groups had bleeding events (p=0.368) during the follow-up. Conclusion: The safety and effectiveness of catheter ablation of AF were comparable between the patients with mechanical MVR and bioprosthetic MVR.

Background: CLBBB and AF are not uncommon coexisted. The impact of CLBBB on long-term prognosis of catheter ablation of AF has not been well determined. Objectives: This study aims to explore the long-term outcomes of patients with atrial fibrillation (AF) and complete left bundle branch block (CLBBB) after catheter ablation. Methods: Forty-two patients with CLBBB of the 11,752 patients who underwent catheter ablation of AF from 2011 to 2020 were enrolled as CLBBB group. After propensity score matching in a 1:4 ratio, 168 AF patients without CLBBB were enrolled as Non-CLBBB group. The primary endpoint was a composite of stroke, all-cause mortality, and cardiovascular hospitalization. The secondary endpoint was AF recurrence after single ablation. Results: The incidence of the primary endpoint in the CLBBB group was significantly higher than in the Non-CLBBB group (21.4% vs. 6.5%, HR 3.98, 95%CI 1.64-9.64, P = 0.002). The recurrence rates in the CLBBB group and the Non-CLBBB group were 54.8% and 31.5% (HR 1.71, 95%CI 1.04-2.79, P = 0.034), respectively. Multivariate analysis showed that CLBBB was an independent risk factor for both primary endpoint (HR 2.92, 95%CI 1.17-3.34, P = 0.022) and secondary endpoint (HR 2.19, 95%CI 1.09-4.40, P = 0.031) in patients with AF after catheter ablation. Conclusions: CLBBB significantly increased the risk of a composite endpoint of stroke, all-cause mortality, and cardiovascular hospitalization after catheter ablation in patients with AF. CLBBB also independently predicted recurrence in these patients.