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: In atrial fibrillation (AF) patients, breakthrough stroke is not uncommon and represents an important subgroup due to its high stroke recurrence rate and mortality. However, no reliable tool exists for assessing stroke risk in anticoagulated paroxysmal AF (PAF) patients. While LOXL2 is implicated in atrial fibrosis, a key pathological substrate for atrial thrombus, its predictive value for stroke remains unclear. Objective: To investigate predictive value of serum LOXL2 levels for breakthrough stroke risk in PAF patients. Methods: We consecutively enrolled 197 anticoagulated PAF patients. The serum level of LOXL2 were quantified via ELISA. Patients were stratified into LOXL2+ and LOXL2− groups based on the median of their baseline LOXL2 (275.9 pg/mL). Stroke events were recorded over a median follow-up of 3.9 years. Predictive models incorporating LOXL2, age, and CHA2DS2-VASc were evaluated using ROC, NRI, and DCA. Results：During follow-up, 24 patients (12.2%) experienced stroke. LOXL2 levels were significantly higher in stroke cases (P = 0.006). Multivariable Cox analysis identified LOXL2 as an independent risk factor (P < 0.001). Kaplan-Meier and Nelson-Aalen cumulative hazard analyses further confirmed the contribution of LOXL2 for elevated stroke risk. A prediction model, incorporating both LOXL2 and age, achieved the highest predictive accuracy (AUC = 0.842), significantly improving risk stratification over CHA2DS2-VASc (NRI = 15.0%, P < 0.001). Conclusion: Elevated LOXL2 is independently associated with breakthrough stroke risk in PAF patients. Incorporating LOXL2 and age enhances predictive accuracy, offering a novel tool for personalized stroke risk stratification in AF patients despite anticoagulation medication.

Background: The anterior and lateral position of the anterolateral papillary muscle (ALPM) has found to be reached with better catheter stability and less mechanical bumping via the transseptal (TS) compared to the retrograde aortic (RA) approach. Aim: To compare the TS and RA approaches on mapping and ablation of ventricular arrhythmias (VAs) arising from ALPMs. Methods: Thirty-two patients with ALPM-VAs undergoing mapping and ablation via the TS approach were included and compared with 31 patients via the RA approach within the same period. Acute success was compared, as well as other outcomes including misinterpreted mapping results due to bumping, radiofrequency (RF) attempts, procedural time and success rate at 12 months’ follow-up. Results: Acute success was achieved in more cases in the TS group (96.4% vs 72.0%, P=0.020). During activation mapping, bump-provoked premature ventricular complexes (PVCs) misinterpreted as clinical PVCs were more common in the RA group (30.0% vs 58.3%, P=0.036), leading to more RF attempts (3.5±2.7 vs 7.2±6.8, P=0.006). Suppression of VAs were finally achieved in the unsuccessful cases by changing to the alternative approach, but the procedural time was significantly less in the TS group (90.0±33.0 vs 113.7±41.1min, P=0.027) with less need to change the approach, although follow-up success rates were similar (75.0% vs 71.0%, P=0.718). Conclusion: A TS rather than RA approach as the initial approach appears to facilitate mapping and ablation of ALPM-VAs, specifically by decreasing the possibility of misleading mapping results caused by bump-provoked PVC, and increase the acute success rate thereby.

Abstract Introduction: Linear ablation in addition to pulmonary vein antrum isolation (PVAI) has failed to improve the success rate for persistent atrial fibrillation (PeAF), due to incomplete block of ablation lines, especially in the mitral isthmus (MI). Methods and results: The study enrolled 191 patients (66 in group 1 and 125 in group 2). In group 1, EI-VOM was firstly performed, followed by radiofrequency (RF) applications targeting bilateral PVAI and bidirectional block in the roofline, cavotricuspid isthmus, and MI. In group 2, PVAI and the three linear ablations were completed using only RF energy. MI block was achieved in 63(95.5%) and 101(80.8%) patients in group 1 and 2, respectively (p=0.006). Patients in group 1 had shorter ablation time for left pulmonary vein antrum (8.15 min vs 12.59 min, p<0.001) and MI (7.0 min vs 11.8 min, p<0.001) and required less cardioversion (50(78.5%) vs 113(90.4%), p=0.007). During the 12-month follow-up, 58 (87.9%) patients were free from AF/AT in group 1 compared with 81 (64.8%) in group 2 (p<0.001). In multivariate cox regression, the ‘upgraded 2C3L’ procedure is associated with a lower recurrence rate (HR 0.27, 95%CI 0.12-0.59). Conclusion: Compared with the conventional ‘2C3L’ approach, the ‘upgraded 2C3L’ approach has higher effectiveness for ablation of PeAF.

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.