Cerebral thrombo-embolism is a dreaded complication of pulmonary vein isolation (PVI) for atrial fibrillation; its surrogate, silent cerebral embolism (SCE) can be detected by diffusion-weighted brain magnetic resonance imaging (bMRI). Initial investigations have raised a concern that very high-power, short-duration (vHPSD; 90 W/4 s) temperature-controlled PVI with the QDOT Micro catheter may be associated with a higher incidence of SCE compared with low-power long-duration ablation. We aimed to assess the incidence of procedural complications of vHPSD PVI with an emphasis on cerebral safety. We enrolled 328 consecutive patients undergoing their PVI procedure using vHPSD. A subgroup of 61 consecutive patients underwent diffusion-weighted bMRI within 24 h of the procedure, and incidence and predictors of SCE were studied. The mean procedure time and left atrial dwell time for the overall cohort were 69.6 ± 24.1 and 46.5 ± 21.5 min, respectively. First-pass isolation was achieved in 82%. No stroke or transient ischaemic attack occurred. Silent cerebral embolism was identified in 5 of 61 patients (8.2%). Silent cerebral embolism following procedures was significantly associated with lower baseline generator impedance (105.8 vs. 112.6 Ω, P < 0.0001) and with intermittent loss of catheter–tissue contact during ablation (14.1% vs. 6.1%, P < 0.0001). Very high-power, short-duration PVI is a safe technique with an excellent acute success rate. Silent cerebral embolism incidence in our cohort was below the previously reported range, with no clinically overt cerebral complications. Lower baseline generator impedance and loss of contact during ablation may contribute to a higher risk of SCEs.

BACKGROUND: High-power short-duration ablation has shown impressive efficacy and safety for pulmonary vein isolation (PVI); however, initial efficacy results with very high power short-duration ablation were discouraging. This study compared the long-term durability of PVI performed with a 90- versus 50-W power setting. METHODS: Patients were randomized 1:1 to undergo PVI with the QDOT catheter using a power setting of 90 or 50 W. Three months after the index procedure, patients underwent a repeat electrophysiology study to identify pulmonary vein reconnections. Patients were followed for 12 months to detect AF recurrences. RESULTS: We included 46 patients (mean age, 64 years; women, 48%). Procedure (76 versus 84 minutes; P =0.02), left atrial dwell (63 versus 71 minutes; P =0.01), and radiofrequency (303 versus 1040 seconds; P <0.0001) times were shorter with 90- versus 50-W procedures, while the number of radiofrequency applications was higher with 90 versus 50 W (77 versus 67; P =0.01). There was no difference in first-pass isolation (83% versus 82%; P =1.0) or acute reconnection (4% versus 14%; P =0.3) rates between 90 and 50 W. Forty patients underwent a repeat electrophysiology study. Durable PVI on a per PV basis was present in 72/78 (92%) versus 68/77 (88%) PVs in the 90- and 50-W energy setting groups, respectively; effect size: 72/78−68/77=0.040, lower 95% CI=−0.051 (noninferiority limit=−0.1, ie, noninferiority is met). No complications occurred. There was no difference in 12-month atrial fibrillation-free survival between the 90- and 50-W groups ( P =0.2). CONCLUSIONS: Similarly high rates of durable PVI and arrhythmia-free survival were achieved with 90 and 50 W. Procedure, left atrial dwell, and radiofrequency times were shorter with 90 W compared with 50 W. The sample size is too small to conclude the safety and long-term efficacy of the high and very high-power short-duration PVI; further studies are needed to address this topic. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT05459831.

Introduction: The role of the spatial relationship between the left superior pulmonary vein (LSPV) and left atrial appendage (LAA) is unknown. We sought to evaluate whether an abutting LAA and LSPV play a role in AF recurrence after catheter ablation for paroxysmal AF.Methods: Consecutive patients, who underwent initial point-by-point radiofrequency catheter ablation for paroxysmal AF at the Heart and Vascular Center of Semmelweis University, Budapest, Hungary, between January of 2014 and December of 2017, were enrolled in the study. All patients underwent pre-procedural cardiac CT to assess left atrial (LA) and pulmonary vein (PV) anatomy. Abutting LAA-LSPV was defined as cases when the minimum distance between the LSPV and LAA was less than 2 mm.Results: We included 428 patients (60.7 ± 10.8 years, 35.5% female) in the analysis. AF recurrence rate was 33.4%, with a median recurrence-free time of 21.2 (8.8–43.0) months. In the univariable analysis, female sex (HR = 1.45; 95%CI = 1.04–2.01; p = 0.028), LAA flow velocity (HR = 1.01; 95%CI = 1.00–1.02; p = 0.022), LAA orifice area (HR = 1.00; 95%CI = 1.00–1.00; p = 0.028) and abutting LAA-LSPV (HR = 1.53; 95%CI = 1.09–2.14; p = 0.013) were associated with AF recurrence. In the multivariable analysis, abutting LAA-LSPV (adjusted HR = 1.55; 95%CI = 1.04–2.31; p = 0.030) was the only independent predictor of AF recurrence.Conclusion: Abutting LAA-LSPV predisposes patients to have a higher chance for arrhythmia recurrence after catheter ablation for paroxysmal AF.

Background and aims: Left atrial appendage (LAA) thrombus is the primary cause of stroke and systemic embolism in atrial fibrillation (AF). Non-vitamin-K oral anticoagulants (NOACs) effectively reduce LAA thrombus prevalence and stroke risk. However, the optimal treatment of a NOAC-resistant thrombus remains unclear. We aimed to evaluate therapeutic strategies for resolving LAA thrombus in patients on optimal NOAC therapy. Methods: We retrospectively analyzed patients scheduled for cardioversion or catheter ablation of AF between 2014 and 2023 with LAA thrombus on transesophageal echocardiography (TEE) despite being on optimal NOAC therapy. We assessed how the applied management strategy affected thrombus resolution. Results: Among the analyzed 120 patients, a change to a different NOAC occurred in 41% of cases, a transition to a VKA in 30%, and the supplementation with antiplatelet therapy in 11%. In contrast, 18% of the patients received unchanged therapy. Follow-up imaging at 65 [44 – 95] days showed successful thrombus resolution in 92 (77%) of cases, predicted by a lower CHA2DS2-VASc score ( p = 0.01). Any modification of antithrombotic therapy was an independent predictor of thrombus resolution (OR 5.28 [1.55–18], p = 0.01). Of the four strategies, there was a trend toward better thrombus resolution with switching to a VKA (OR 3.23 [1.03–10.1], p = 0.04). Conclusion: Resolution of LAA thrombus in patients already on adequate NOAC treatment may require a revision of the anticoagulation strategy. In addition, transitioning from NOAC to VKA might be considered. Graphical

The predictive role of local impedance (LI) drop in lesion formation using a novel contact force sensing ablation catheter was recently described. The purpose of our current study was to assess the temporal characteristics of LI drop during ablation and its correlation with acute lesion efficacy. Point-by-point pulmonary vein isolation was performed. The efficacy of applications was determined by pacing along the circular ablation line and assessing loss of capture. Local impedance, contact force, and catheter position data with high resolution were analysed and compared in successful and unsuccessful applications. Five hundred and fifty-nine successful and 84 unsuccessful applications were analysed. The successful applications showed higher baseline LI (P < 0.001) and larger LI drop during ablation (P < 0.001, for all). In case of unsuccessful applications, after a moderate but significant drop from baseline to the 2 s time point (153 vs. 145 Ω, P < 0.001), LI did not change further (P = 0.99). Contradictorily, in case of successful applications, the LI significantly decreased further (baseline–2 s–10 s: 161–150–141 Ω, P < 0.001 for all). The optimal cut-point for the LI drop indicating unsuccessful application was <9 Ω at the 4-s time point [AUC = 0.73 (0.67–0.76), P < 0.001]. Failing to reach this cut-point predicted unsuccessful applications [OR 3.82 (2.34–6.25); P < 0.001]. A rapid and enduring drop of the LI may predict effective lesion formation, while slightly changing or unchanged LI is associated with unsuccessful applications. A moderate LI drop during the first 4 s of radiofrequency application predicts ineffective radiofrequency delivery.

Aims: We aimed to establish sex-specific predictors for 1-year VT recurrence and 1-year all-cause mortality in patients with structural heart disease undergoing catheter ablation.Methods: We analyzed data of 299 patients recorded in our structured registry. These included medical history, echocardiography parameters, laboratory results, VT properties, procedural data.Results: Out of the 299 patients, 34 (11%) were female. No significant difference was found between women and men in terms of VT recurrence (p = 0.74) or mortality (p = 0.07). In females, severe mitral regurgitation (MR), tricuspid regurgitation (TR), presentation with incessant VT, and preprocedural electrical storm (ES) were associated with increased risk of VT recurrence. Diabetes, implanted CRT, VT with hemodynamic instability, ES and advanced MR were the risk factors of mortality in women. ACEi/ARB use predicted a favorable outcome in both endpoints among females. In men, independent predictors of VT recurrence were the composite parameter of ES and multiple ICD therapies, presentation with incessant VT, severe MR, while independent predictors of mortality were age, LVEF, creatinine and previously implanted CRT.Conclusion: According to our investigation, there are pronounced sex differences in predictors of recurrence and mortality following VT ablation.