BACKGROUND:The optimal long-term antithrombotic strategy in patients with atrial fibrillation (AF) and coronary artery disease (CAD) after successful catheter ablation (CA) remains uncertain. OBJECTIVE:This study aimed to compare the effectiveness and safety of single antiplatelet therapy (SAPT) vs oral anticoagulation (OAC) monotherapy in this population. METHODS:This cohort study used a target trial emulation framework based on data from the China Atrial Fibrillation Registry. Patients with nonvalvular AF and CAD who underwent index CA were screened. Those free from AF recurrence, thromboembolism, or bleeding 12 months after ablation were included and categorized according to antithrombotic regimen at the 12-month landmark. The primary effectiveness outcome was thromboembolism (ischemic stroke or systemic embolism), and the primary safety outcome was bleeding (International Society on Thrombosis and Haemostasis major or clinically relevant nonmajor bleeding). Secondary outcomes included all-cause mortality and net clinical benefit. Inverse probability of treatment weighting was used for confounding adjustment. RESULTS:Among 998 patients (mean age 66.8 years; 26.5% women), 706 received SAPT and 292 OAC monotherapy. Over a mean follow-up of 3.0 years, 19 thromboembolic and 29 bleeding events occurred. After weighting, no statistically significant difference in thromboembolism was observed (hazard ratio [HR], 0.54; 95% confidence interval [CI], 0.18-1.61), whereas SAPT was associated with lower bleeding risk (HR, 0.40; 95% CI, 0.18-0.91). No significant differences were observed in mortality (HR, 0.77; 95% CI, 0.35-1.72) or net clinical benefit (HR, 0.66; 95% CI, 0.36-1.20). CONCLUSION:In this stable postablation population with AF and CAD, SAPT was associated with lower bleeding risk vs OAC monotherapy, whereas no statistically significant difference in thromboembolism was observed.

INTRODUCTION:The cryoballoon catheter is a gold-standard single-shot device for pulmonary vein isolation (PVI). Pulsed-field ablation (PFA) is a tissue-selective, nonthermal cardiac ablation modality. We assessed the preclinical safety and durability of a novel conformal, balloon-shaped, single-shot PFA catheter for PVI and circular atrial lesions. METHODS:A 13 Fr balloon-shaped PFA catheter (PFBalloonTM, 20 electrodes, 24 mm diameter, EnChannel Medical) was applied using a biphasic waveform of microsecond scale (± 750 V, 4.9 s per application). In 10 swine, superior vena cava (SVC), left superior PV (LSPV), right superior PV (RSPV) and right atrial appendage (RAA) were targeted for isolation. Localization of PFBalloon was evaluated by fluoroscopy and intracardiac echocardiography (ICE). PFA was delivered in a novel tailored configuration (small ring, large ring, or global pulse) to minimize diaphragm stimulation and optimize pulse efficiency. Five swine were assessed at 30 days post-procedure for lesion durability, gross pathology, and histologic examination, while the remaining five swine were evaluated at 90 days to assess longer term outcomes. RESULTS:In all 10 swine, PFA resulted in 100% successful acute isolation of the SVC, RSPV, and LSPV using 4.2 ± 0.6, 5.0 ± 1.1, and 4.4 ± 1.8 applications per vein, respectively, and acute isolation of RAA in 9/10 swine using 5.3 ± 2.0 applications. At 30 days post-procedure, 14 out of 20 targeted sites (70.0%) remained isolated in five pigs. At 90 days, 19 out of 20 sites (95.0%) remained isolated in the remaining five pigs. The overall pulse configurations were 9.0% small ring, 25.4% large ring, and 65.6% global. PFA did not affect phrenic nerve function, with very few microbubbles recorded on ICE. No major complications were observed. CONCLUSIONS:In this preclinical study, a novel conformal, balloon-shaped catheter designed for single-shot PVI can create durable isolation without complications.

QuestionIs discontinuation of guideline-directed medical therapy (GDMT) after catheter ablation feasible and safe in patients with atrial fibrillation (AF) with improved cardiac function?FindingsIn this randomized clinical trial of 50 patients with AF and heart failure (HF) with improved ejection fraction (suspected with AF-mediated cardiomyopathy), phased GDMT withdrawal in those with normalized left ventricular ejection fraction and sinus rhythm resulted in HF deterioration in 3 of 23 patients (13%) compared with none in the continuation group. This was not a statistically significant difference.MeaningAlthough this study did not find significantly more HF deterioration in patients who discontinued GDMT vs those who continued, further studies are needed to determine whether GDMT can be safely discontinued in this population. This pilot randomized clinical trial assesses whether phased withdrawal of heart failure medication in patients who have undergone catheter ablation for atrial fibrillation (AF) and experienced improvements in cardiac function is feasible and safe. ImportanceWithdrawal of guideline-directed medical therapy (GDMT) for heart failure (HF) is common after atrial fibrillation (AF) catheter ablation and recovery of cardiac function, but safety remains uncertain.ObjectiveTo assess the feasibility and safety of phased GDMT withdrawal in patients with AF with highly suspected AF-mediated cardiomyopathy after catheter ablation.Design, Setting, and ParticipantsThis open-label pilot randomized clinical trial included adult patients who were enrolled and randomized from April 13, 2023, to September 19, 2024, at Beijing Anzhen Hospital, China, with a 6-month follow-up. Eligible patients were those with suspected AF-mediated cardiomyopathy at 3 months after ablation, defined by sinus rhythm at 3 months after ablation, absence of other suspected cardiomyopathies, improvement of left ventricular ejection fraction (LVEF) from 45% or less to 55% or more, normalized LV end-diastolic diameter (LVEDD), N-terminal pro-brain natriuretic peptide (NT-proBNP) levels less than 250 ng/L, and no HF symptoms or signs.InterventionsPatients were randomly assigned in a 1:1 ratio to phased GDMT withdrawal or GDMT continuation.Main Outcomes and MeasuresThe primary end point was HF deterioration, defined as LVEF decline more than 10% to less than 55%, LVEDD increase more than 10% and beyond normal, NT-proBNP levels doubling to more than 400 ng/L, or worsening HF signs or symptoms. Secondary outcomes included cardiovascular events, changes in echocardiographic and cardiac magnetic resonance (CMR) parameters, NT-proBNP levels, Kansas City Cardiomyopathy Questionnaire-12 (KCCQ-12) scores, atrial arrhythmia recurrence, and adverse drug events.ResultsAmong 50 patients enrolled and randomized, 47 completed follow-up (median [IQR] age, 56.0 [48.0-60.5] years; 37 males [78.7%]), including 23 (48.9%) in the GDMT withdrawal group and 24 (51.1%) in the continuation group. HF deterioration occurred in 3 patients with GDMT withdrawal (13.0%) and 0 with GDMT continuation (0%) (P = .11). Early GDMT reinitiation in 3 patients with HF deterioration showed recovery of LVEF or NT-proBNP. No cardiovascular events occurred. Median (IQR) echocardiographic (LVEF: 0% [-3.0% to 3.5%] vs 1.5% [-5.0% to 5.0%]), CMR (LVEF: -2.1% [-7.2% to 4.6%] vs 2.9% [-2.6% to 7.4%]), and KCCQ-12 score (0 [0 to 0.5] vs 0) changes were similar between groups. Median (IQR) NT-proBNP levels declined more in the GDMT continuation group than the withdrawal group (-25.7 [-33.6 to -6.7] pg/mL vs 2.7 [-21.4 to 24.2] pg/mL; P = .03). Adverse drug events were more frequent in the GDMT continuation group than the withdrawal group (5 [20.8%] vs 0 [0%]; P = .050). Arrhythmia recurrence rates were comparable (GDMT withdrawal: 3 [13.0%] vs continuation: 3 [12.5%]).Conclusions and RelevanceIn this pilot randomized clinical trial of carefully selected patients with AF with normalized cardiac function and sinus rhythm after catheter ablation, 13% of patients with GDMT withdrawal experienced HF deterioration, whereas drug-related complications were more common in the continuation group, suggesting that further studies are needed to determine whether GDMT can be safely discontinued in this population.Trial RegistrationChinese Clinical Trial Registry Identifier: ChiCTR2300077439

The role of prophylactic cavotricuspid isthmus (CTI) ablation remains controversial in atrial fibrillation (AF) patients without atrial flutter (AFL). Given the strong association between AF, AFL, and age, this study aimed to evaluate the impact of additional CTI ablation on recurrence-free survival, with a focus on age-stratified outcomes. Between June 2020 and June 2022, 1226 paroxysmal AF patients without AFL who underwent first AF catheter ablation at Beijing Anzhen Hospital were enrolled. 899 patients underwent pulmonary vein isolation (PVI) alone (PVI group) and remaining 327 patients underwent additional CTI ablation (PVI + CTI group). Both groups were stratified into four age quartiles to assess age-related recurrence risk. Over a median 36.6-month follow-up, prophylactic CTI ablation did not have a better outcome in overall population. In the PVI + CTI group, the oldest age quartile (> 70 years) was independently associated with a lower risk of recurrence compared with the youngest quartile (≤ 56 years; adjusted HR 0.41, 95

This study investigated the association between serum uric acid (UA) levels and atrial fibrillation (AF) burden in Chinese patients with AF. In this cross-sectional study, AF burden was defined as the proportion of AF duration to total monitoring time, recorded by a patch device over ≥24 hours. Serum UA levels were measured at the start of monitoring. Multivariate logistic regression was used to assess associations. A total of 952 patients with AF (66.4% women; median age 64 years) were included. A 1-SD increase in UA (91.4 μmol/L) was associated with elevated risk of persistent AF (adjusted OR: 1.32; 95% CI: 1.12–1.55; P < 0.001). The highest UA quintile had a greater risk of persistent AF than the lowest quintile of patients (adjusted OR: 2.43; 95% CI: 1.49–3.98; P for trend < 0.001). Serum UA levels are positively associated with AF burden in a dose-dependent manner. UA might serve as an accessible biomarker and potential therapeutic target for AF burden assessment.

Objectives: Real-world data on oral anticoagulant (OAC) use patterns and dosing appropriateness in patients with nonvalvular atrial fibrillation (AF) remain limited in China. This study aims to characterize trends in OAC prescribing and assess the dosing appropriateness of direct oral anticoagulants (DOAC) in nonvalvular AF. Methods: This is a retrospective secondary analysis of the prospective China-AF Registry (ChiCTR-OCH-13003729, registered on October 22, 2013), using data from patients with nonvalvular AF who were discharged on OAC between 2011 and 2022. Real-world trends in warfarin versus DOAC use and dosing appropriateness were evaluated. Predictors of inappropriate DOAC dosing were identified. Results: Among the included patients, 10,205 received warfarin and 15,084 received DOAC. The proportion of DOAC prescriptions increased from 0% in 2011 to 98% after 2020, whereas warfarin use declined from 99.74% to 1.99%. The shift accelerated after 2017, coinciding with the inclusion of dabigatran and rivaroxaban into the National Reimbursement Drug List. DOAC were less frequently prescribed to high-risk patients, including those with higher CHA 2 DS 2 -VASc (congestive heart failure, hypertension, age [≥75 years earns 2 points, 65–74 years earns 1 point], diabetes mellitus, prior stroke, transient ischemic attack, or thromboembolism [2 points], vascular disease [e.g., prior myocardial infarction, peripheral artery disease], and female sex category) and hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly (>65 years), drugs/alcohol use (HAS-BLED) scores, older age, and lower creatinine clearance (all P for trend < 0.05). Inappropriate dosing was more prevalent in these higher-risk groups ( P for trend < 0.001). Older age was independently associated with inappropriate dosing (per 10 years, odds ratio [OR] = 1.39; 95% confidence interval [CI], 1.29–1.51; P < 0.001). In contrast, male (OR = 0.77; 95% CI, 0.65–0.91; P = 0.002), prescriptions post-2017 (OR = 0.12; 95% CI, 0.07–0.20; P < 0.001), persistent AF (OR = 0.78; 95% CI, 0.67–0.92; P = 0.002), and dabigatran use (OR = 0.020; 95% CI, 0.020–0.028; P < 0.001) were associated with lower odds of inappropriate dosing. Conclusions: From 2011 to 2022, OAC prescribing in China shifted dramatically from warfarin to DOAC, with more rapid DOAC adoption after the 2017 National Reimbursement Drug List update. Although DOAC dosing appropriateness improved over time, inappropriate dosing remained common in higher-risk patients, particularly older adults.

BACKGROUND:The impact of body mass index (BMI) on the outcomes of radiofrequency catheter ablation (RFCA), including atrial fibrillation (AF) recurrence rate, cardiac remodelling, and quality of life (QoL), remains uncertain. METHODS:We analysed 12 104 first-time RFCA patients from the China-AF registry, stratified by BMI: under/normal weight (< 25 kg/m2), overweight (25-29.9 kg/m2), and obese (≥ 30 kg/m2). The primary outcome was AF recurrence. Exploratory outcomes included 12-month echocardiographic parameters and Atrial Fibrillation Effect on Quality-of-Life (AFEQT) scores. Multivariable Cox regression, median regression, restricted cubic splines (RCS), and subgroup analyses were performed. RESULTS:In this cohort (median age 61.55 years, 32.6% female), obese patients were significantly younger with higher comorbidities burdens. Over a median follow-up of 47.5 months, 4932 (40.8%) patients experienced AF recurrence. BMI exhibited a linear, dose-dependent association with recurrence risk (fully adjusted HR 1.01, 95% CI, 1.00-1.02; obese HR 1.16, 95% CI: 1.05-1.28), consistent across primary analyses, sensitivity analyses using Chinese BMI classification standards, and subgroups (with stronger associations in males, < 65 years, persistent AF), without significant interactions across these subgroups (all pinteraction > 0.05). Exploratory analyses suggested obesity was linked to nonlinearly higher 12-month left ventricular end-diastolic diameter (LVEDD; 2.17 mm, 95% CI: 0.79-3.55) and left ventricular wall thickness (LVWT; 0.81 mm, 95% CI: 0.45-1.17) versus under/normal-weight, with nonlinear association in primary analysis (both pnonlinear < 0.05). CONCLUSION:Higher BMI exhibits a linear association with AF recurrence post-RFCA. Obesity is linked to nonlinear adverse remodelling (LVEDD and LVWT).

Abstract. Atrial fibrillation (AF) and heart failure (HF) are major public health issues and are linked by a complex, bidirectional relationship. AF can contribute to the development of HF through diverse mechanisms, including tachycardia, irregular ventricular rhythm, impaired atrial contraction, and atrioventricular dyssynchronization. In patients with AF-mediated cardiomyopathy (AF-CM), these effects may be reversible with effective rate control or restoration of sinus rhythm. Early diagnosis and intervention offer the potential for the recovery of cardiac function, highlighting the importance of understanding the underlying mechanisms, clinical features, and management strategies for AF-CM. Cardiac imaging, biomarker profiling, continuous rhythm monitoring, and the identification of specific clinical features may facilitate the diagnosis of AF-CM. Catheter ablation has been established as an effective treatment for patients with AF and HF. However, considerable controversy persists regarding the necessity for long-term HF pharmacological therapy following successful ablation. In this review, the current understanding of AF-CM is summarized, with a focus on its mechanisms, clinical features, and management. The role of guideline-directed medical therapy for HF in the long-term management of patients with AF-CM is further discussed.

AIMS:Optimal management of oral anticoagulation (OAC) after atrial fibrillation (AF) ablation remains uncertain. We evaluated thromboembolic and bleeding outcomes associated with OAC discontinuation vs. continuation at a clinically relevant 6-month post-ablation landmark. METHODS AND RESULTS:This target trial emulation used data from a multicentre prospective registry in China. Patients with CHA2DS2-VA scores ≥2, no prior thromboembolism, and no atrial arrhythmia recurrence within 6 months after ablation were classified according to OAC discontinuation or continuation at the 6-month landmark. The primary outcome was the composite of stroke, systemic embolism, and major bleeding. Inverse probability weighting was applied, with intention-to-treat as the primary analysis. Among 8339 patients (mean age 68 years; 40.5% women), 4406 discontinued and 3933 continued OAC. The risk of the primary outcome did not differ significantly between groups [weighted hazard ratio (HR) 0.93; 95% CI 0.67-1.29]. Thromboembolic risk was similarly comparable (HR 0.96; 95% CI 0.69-1.35). Clinically relevant non-major bleeding occurred less frequently after OAC discontinuation (HR 0.68; 95% CI 0.47-0.97). Findings were consistent in sensitivity analyses. Annualized thromboembolic rates after discontinuation were <1% in patients with CHA2DS2-VA scores 2-3 but 1.52% in those with scores ≥4. CONCLUSION:Among patients without prior thromboembolism who remained arrhythmia-free at 6 months after AF ablation, OAC discontinuation was not associated with a difference in the composite outcome of stroke, systemic embolism and major bleeding compared with OAC continuation. Residual risk remained low in patients with CHA2DS2-VA scores 2-3 but exceeded conventional thresholds in those with scores ≥4.

BACKGROUND:Despite the growing use of catheter ablation for atrial fibrillation, large-scale studies assessing the efficacy and safety of oral anticoagulation (OAC) after ablation, particularly in patients with high stroke risk, remain limited. METHODS:This prospective study enrolled consecutive patients from the China-AF (China Atrial Fibrillation) registry between August 2011 and June 2022. Stroke risk was stratified by CHA2DS2-VA score as low (0-1), intermediate (2), or high (≥3). The study end points were thromboembolism (ischemic stroke or systemic embolism), and bleeding (International Society on Thrombosis and Hemostasis major bleeding and clinically relevant non-major bleeding). A 6-month landmark analysis was applied to evaluate the association of OAC with end points using incidence rates and Cox models. RESULTS:Among 13 669 patients (median follow-up, 4.0 years), 2637 continued and 11 032 discontinued OAC at the 6-month landmark. OAC was not associated with reduced thromboembolism risk across low- (adjusted hazard ratio [aHR], 1.11 [95% CI, 0.70-1.77]; P=0.649), intermediate- (aHR, 0.64 [95% CI, 0.36-1.16]; P=0.141) or high-stroke risk patients (aHR, 1.05 [95% CI, 0.74-1.48]; P=0.801). In contrast, continued OAC was associated with higher bleeding risk, including clinically relevant non-major bleeding across stroke risk strata, and International Society on Thrombosis and Hemostasis major bleeding among high-risk patients (aHR, 2.32 [95% CI, 1.19-4.50]; P=0.013). These results were consistent across subgroups and sensitivity analyses. CONCLUSIONS:In this large, real-world cohort of patients with atrial fibrillation undergoing catheter ablation, continued OAC was not associated with lower thromboembolic risk, but with higher major bleeding risk among patients with CHA2DS2-VA scores ≥3. These findings support individualized post-ablation anticoagulation strategies and warrant future investigation. REGISTRATION:URL: https://www.clinicaltrials.gov; Unique Identifier: NCT06987825.

Background:Steam pop is a major safety concern in radiofrequency ablation. The temperature-flow control (TFC) mode may mitigate this risk by precisely monitoring tissue temperature. Objective:This study compared the safety and efficacy of TFC vs power control (PC) under ablation index (AI) guidance, focusing on steam pop incidence and lesion characteristics. Method:In vivo experiments were conducted in 9 swine, with atrial ablations performed under AI control at 500-600 and ventricular ablations at 550-650. Procedural parameters were recorded, and lesion characteristics and steam pops were assessed pathologically. Result:A total of 258 atrial and 117 ventricular ablations were performed in 9 pigs, of which 227 atrial and 102 ventricular ablations met the inclusion criteria. In both chambers, contact force was comparable between TFC and PC groups, but the ablation time was significantly longer with TFC (P < .001). Lesion dimensions did not differ significantly between groups. The incidence of steam pop was markedly lower with TFC than PC (1.1% vs 9.9%; P < .001), with ventricular pops significantly reduced (3.6% vs 26.1%; P = .001). All TFC-related pops occurred in high-risk anatomic sites. Pathology confirmed comparable nonpop lesions, whereas PC pops showed more cavitation, hemorrhage, and microvascular rupture. Compared with TFC, PC produced greater impedance drop, power, and current, although differences between pop and nonpop lesions were minimal. Conclusion:TFC achieved lesion sizes similar to PC but significantly reduced steam pops at the same AI level, suggesting improved procedural safety.

Atrial fibrillation (AF) increases the risk of stroke and heart failure, yet accurate quantification of AF burden in daily life remains difficult. Although smartwatch photoplethysmography (PPG) supports continuous monitoring, complex rhythms and signal noise can impair burden estimation. We developed an AI-enhanced dual-modal framework that combines continuous watch-based PPG (W-PPG) with intermittent single-lead watch-based ECG (W-ECG). A hybrid convolutional neural network-long short-term memory model uses high-fidelity W-ECG segments as dynamic anchors to correct long-term W-PPG classifications. In this prospective validation study, 1,054 patients with AF undergoing catheter ablation (mean age, 62.1 years) were evaluated against patch-based ECG as the reference standard. After ECG-based correction, the system achieved 98.60% sensitivity and 99.27% specificity. The mean absolute percentage error of AF burden decreased by 23.4%, from 1.11% to 0.85%, while the Pearson correlation remained 0.9988. This dual-modal approach offers a scalable and clinically practical solution for long-term AF monitoring, improving burden estimation beyond PPG-only devices without requiring continuous multi-lead ECG. It may support personalized AF management and large-scale cardiovascular screening in real-world settings. (NCT06552468)

Current evidence is limited concerning the temporal impact of atrial fibrillation (AF) ablation timings on post-ablation outcomes. Patients who experienced ablation in the CABANA trial were enrolled in our analysis. Diagnosis to ablation time (DAT) was calculated from the date when the initial AF episode was documented. The primary endpoint was a composite of death, disabling stroke, serious bleeding or cardiac arrest. Secondary end points included AF recurrence, all-cause mortality, and all-cause mortality or cardiovascular hospitalisation. Associations between DAT and post-ablation outcomes were evaluated by restricted cubic spline (RCS) curves based on Cox models. Out of 1145 patients (median age 67.0 years, interquartile range (IQR) 61.0–72.0; 36.7

AIMS:Though pulsed-field ablation (PFA) has demonstrated an excellent safety profile in reducing collateral injury to the oesophagus and phrenic nerve, it is still associated with specific effects, including electrode heating, haemolysis, and electrolysis due to excessive energy dispersion. This study aims to assess whether saline irrigation during PFA application could mitigate these risks. METHODS AND RESULTS:To comprehensively evaluate the effect of irrigation with the variable-loop circular catheter (VLCC), the following experiments were performed: (i) ex-vivo potato model: to evaluate the lesion depth, bubble formation, and thermal effects in different irrigation regimens; (ii) in vitro blood pool and cardiac ablation: to determine the haemolysis status and tissue temperature change after PFA; (iii) in vivo swine ablation (n = 8), and (iv) clinical randomized trial (n = 25): to compare the efficacy and safety profile between low (4 mL/min) and high (30 mL/min) flow irrigation using the VLCC. Though peak core temperatures at 5 mm depth were all < 50°C under low- and high-irrigation, high irrigation significantly mitigated the instant electrode and deep tissue heating both in the potato and isolated cardiac models. Ex vivo potato slices showed that high-flow irrigation produced the deepest lesion sets when compared to low-flow irrigation (5.94 ± 0.29 mm vs. 5.36 ± 0.33 mm, P = 0.043). Assessment from a high-speed camera and bubble detector demonstrated that high-flow irrigation significantly reduced the total number of gaseous bubbles (54.50 IQR 53.00-56.75 vs. 82.00 IQR 72.00-83.00, P < 0.001) and eliminated the occurrence of larger bubbles. The high-flow irrigation group showed a smaller increase in the level of free haemoglobin immediately after the procedure across the blood pool, swine, and clinical models. Haptoglobin and lactate dehydrogenase levels were also attenuated by high irrigation in the in vivo swine model and clinical trial. One swine in the low-irrigation group developed an acute cerebral lesion (3 mm). The clinical trial confirmed that the incidence of silent cerebral lesions was significantly lower in the high-flow irrigation group (16.7% vs. 66.7%, P = 0.036). CONCLUSION:Proper saline irrigation during PFA with VLCC may mitigate electrode-associated haemolysis, reduce electrode and tissue temperature, limit bubble aggregation, and be associated with a lower incidence of silent cerebral lesions, the clinical significance of which remains unclear.

Aim: To evaluate the long-term impact of obstructive sleep apnea (OSA) risk profile on atrial fibrillation (AF) recurrence after catheter ablation in patients with paroxysmal AF. Methods: This prospective study enrolled 161 patients with paroxysmal AF undergoing initial ablation. Patients were stratified by the Berlin Questionnaire (BQ) into high-risk (n = 94) and low-risk (n = 67) OSA groups. Atrial tachyarrhythmias occurring within the initial three months were defined as early recurrence, whereas recurrence beyond three months was defined as late recurrence. A subgroup of 71 patients with recurrence underwent a redo ablation. Results: After 16.1 ± 0.4 years, multivariable models revealed that a BQ-defined high OSA risk was independently associated with early recurrence (odds ratio [OR] 1.99, 95% confidence interval [CI] 1.02-3.86, P = 0.043), whereas it was not independently associated with late recurrence after the initial procedure (hazard ratio [HR] 1.05, 95%CI: 0.70-1.57, P = 0.810). Cox regression identified early recurrence (HR 2.95, 95%CI: 1.99-4.39, P < 0.001) and baseline high-sensitivity C-reactive protein (hs-CRP; HR 1.02, 95%CI: 1.00-1.03, P = 0.022) as independent predictors of late recurrence after the initial procedure. Following redo ablation, early recurrence remained a strong independent predictor (HR 5.93, 95%CI: 2.13-16.50, P < 0.001). Conclusions: The BQ-defined high OSA risk was an independent predictor of early recurrence; however, it was not significantly associated with late recurrence after AF ablation. Early recurrence was the strongest predictor of long-term outcome, highlighting the importance of management during the post-procedural blanking period.

BACKGROUND:Obesity is a modifiable risk factor for atrial fibrillation (AF), but its relationship with acute procedural response and long-term rhythm durability after ablation for persistent AF (PeAF) remains incompletely defined. OBJECTIVE:To evaluate the association of body mass index (BMI) with acute AF termination and long-term atrial arrhythmia recurrence after first-time radiofrequency catheter ablation for PeAF. METHODS:We analyzed prospective data from 7559 consecutive patients with clinically documented PeAF undergoing first-time radiofrequency catheter ablation between January 2018 and March 2025. Patients were classified according to World Health Organization BMI categories. The primary outcome was atrial arrhythmia recurrence after a 3-month blanking period. RESULTS:During a median follow-up of 41 months, atrial arrhythmia recurrence occurred in 3494 patients (46.2%). In the fully adjusted model, higher BMI was associated with recurrence as a continuous variable (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.02-1.04). Compared with normal-weight patients, patients with overweight and obesity had higher recurrence risks (HR, 1.15; 95% CI, 1.06-1.24; and HR, 1.31; 95% CI, 1.18-1.45, respectively). Acute AF termination occurred in 832 patients (11.0%) and decreased with increasing BMI. Higher BMI was associated with lower odds of acute AF termination (odds ratio, 0.95; 95% CI, 0.93-0.97). Findings were consistent across sensitivity analyses. CONCLUSION:In patients with PeAF undergoing first-time radiofrequency ablation, higher BMI was associated with lower acute AF termination and increased long-term recurrence. BMI may serve as a practical marker for preprocedural risk stratification.

BACKGROUND:nGENTM generator is a new-generation radiofrequency (RF) energy device widely used in the catheter ablation of atrial fibrillation. Compared with SMARTABLATETM (SMA), a lower displayed impedance of nGEN can be observed during electrophysiology procedures. However, whether this impedance disparity affects ablation lesion size remains unelucidated. METHODS:Fresh ex vivo porcine hearts were used for the experiment. Impedance of the same marked points on porcine left ventricle was measured using both generators. Ablations were performed at varying RF power (35 W, 45 W) and ablation index (AI; 400, 450, 550). Five lesions for each combination of settings were created with both generators and their lesion sizes were compared. RESULTS:The impedance of nGEN was notably lower than SMA (78.1±3.2Ω vs. 87.5±4.2Ω, p < 0.05). Under identical application settings, lesion depth, maximum length, and volume did not differ significantly between the two generators in any of the groups. Surface measurements of maximum diameter and area also showed no significant differences except at 45 W/AI  =  450, where nGEN generated significantly larger values than SMA (6.5 [6.4-6.9]mm vs. 5.8 [5.5-6.0]mm; 22.8 [22.5-24.4]mm2 vs. 20.3 [18.8-20.5]mm2; all p < 0.05). Lesion depth, maximum length, and volume of both generators were strongly correlated with AI (nGEN: r = 0.796, r = 0.657, r = 0.769; SMA: r = 0.794, r = 0.678, r = 0.733; all p < 0.05). CONCLUSIONS:nGEN displays lower impedance than SMA. Lesion sizes are overall comparable between the two generators in AI-guided ablation, with the exception of surface measurements at 45 W/AI  =  450.

BACKGROUND:Nonvalvular atrial fibrillation (NVAF) patients with low CHA2DS2-VASc scores still have a risk of atrial thrombus formation. This study aims to identify these patients' risk factors for intracardiac thrombus or sludge. METHODS:We conducted a retrospective study of 919 consecutive hospitalized NVAF or atrial flutter patients with a CHA2DS2-Vas score ≤ 1 (male) and ≤ 2 (female) who underwent transesophageal echocardiogram (TEE) before catheter ablation at Beijing An Zhen Hospital from November 2016 to December 2017. We collected the clinical and echocardiographic characteristics of the patients. RESULTS:Excluding seven patients with hypertrophic cardiomyopathy, 919 patients, including 17 identified left atrial appendage (LAA) thrombus/sludge and 902 without LAA thrombus/sludge, were included. Among 17 patients with LAA thrombus/sludge, 16 (94.1%) had non-paroxysmal AF. A subgroup analysis was conducted in 403 non-paroxysmal atrial fibrillation (AF) patients. 87.8% had spontaneous echo contrast (SEC), 59.3% had severe or more severe SEC, and 4.0% had thrombus/sludge. In the multivariable model, female (odds ratio [OR] 4.612, 95% [CI] 1.454-14.627, p = 0.009) and LA diameter ≥ 45 mm (OR 13.340, [CI] 3.601, 49.415, p < 0.001) remained significantly independently associated with LAA thrombus/sludge. CONCLUSION:Among patients with NVAF and CHA2DS2-VASc scores ≤ 1 (male) and ≤ 2 (female), those non-paroxysmal AF patients who were female and had an LA ≥ 45 mm still had a risk of LAA thrombus/sludge formation.