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: Atrial fibrillation (AF) is common in abdominal solid organ transplant recipients and a cause of morbidity and mortality in this population. However, the outcomes of catheter ablation (CA) in transplant recipients with AF remain unclear. This study aimed to elucidate the outcomes of CA in renal and hepatic transplant recipients. Methods and Results: Between 2015 and 2019, 14 transplant recipients (9 with kidney transplantation and 5 with liver transplantation) were enrolled from among 10,741 AF patients and underwent CA at Anzhen Hospital. Another 56 patients matched by age, sex and AF type were selected as the control group (4 controls for each transplant recipient). During a mean follow-up of 30.0±13.3 months after the initial procedure, 10 (71.4%) of the transplant patients, compared to 41 (73.2%) of the control patients, remained free from AF recurrence(P=1.000). A repeated procedure was performed in 1 transplant patient and in 6 control subjects. Consequently, 11 (78.6%) of the transplant patients, compared to 46 (82.1%) of controls, were in sinus rhythm after the repeated ablation (P=0.715). Notably, Kaplan–Meier analysis did not demonstrate any significant differences in the atrial arrhythmia-free rate after the initial and repeated procedure between the two groups. Vascular complications were identified in 1 transplant patient and 2 control subjects, while no life-threatening complications were observed in either group. There was no transient allograft dysfunction in transplant recipients after CA. Conclusion: CA is safe and effective in abdominal solid transplant recipients, and may be an optimal therapeutic strategy for this group.