Pulmonary Vein Isolation Ablation Research Articles

Comparison of pulsed field ablation versus cryoballon and radiofrequency ablation for pulmonary vein isolation in atrial fibrillation patients with heart failure

Abstract Background Pulmonary vein isolation (PVI) is the gold standard for atrial fibrillation (AF) ablation and can be achieved by a variety of technical methodes. While thermal ablation modalities (TA), such as cryoballon (CB) and radiofrequency ablation (RF) have been established as the standard approaches, PFA has been introduced as a nvel non-thermal modality showing comparable safety and procedural efficiency. Despite the high incidence of AF in heart failure (HF) patients, data comparing outcomes of HF patients undergoing PVI by either PFA or thermal ablation (RFA/CB) are limited. Purpose This study’s aim was to compare the efficacy and safety of PFA for AF ablation versus CB/RFA in HF patients. Methods Consecutive HF patients with preserved (HFpEF), mildly reduced (HFmrEF) and reduced (HFrEF) ejection fraction undergoing PVI for AF by either PFA or CB/RFA at our institution were included. The primary end-point was time to death or recurrence of AF. Secondary end-points were periprocedural complications and clinical and echocardiographic parameters. Results We included 140 HF patients who underwent PVI either by PFA (PFA group, 76 patients) or thermal ablation approaches (TA group, 64 patients). Our patients had a mean age of 69 years and were predominantly male (62%). There was no significant difference in the baseline characteristics and in the type of AF between both groups (42% with ParAF, 45% with PersAF) and 13% LSPersAF). The distribution of heart failure types was similar between both groups: HFpEF (PFA: 71%, TA: 75%), HFmrEF (PFA: 21%, TA: 20%) and HFrEF (PFA: 8 %, TA: 5%). After the 365-days follow-up period we observed no significant difference for the primary end-point between both groups (HR: 0.79, 95% CI 0.35-1.78; p=0.575). In total 58% of the PFA patients and 59% of the TA group were still free from AF. While symptom improvement was documented in both groups, patients in the PFA group showed significant improvement of left atrial volume index (p = 0.014), NT-pro BNP levels (p = 0.046), and left ventricular ejection fraction (LVEF) (p = 0.005). Conclusion In this study, PFA and thermal ablation modalities showed comparable results in terms of safety and procedural efficiency in patients with heart failure. Since previous studies have shown that HF patients with AF benefit from PVI using thermal ablation modalities, our results suggest that PFA might also be a promising ablation method in this vulnerable population, inducing left atrial reverse remodeling and thereby contributing to improvement of left ventricular systolic function.

Safety and effectiveness of pulsed field ablation for pulmonary vein isolation in atrial fibrillation patients: a single centre experience

Abstract Introduction Atrial Fibrillation (AF) is the most frequent arrhythmia in the world with an exponentially increasing prevalence. Pulmonary veins (PV) are the primary triggering sites for AF and pulmonary veins isolation (PVI) is currently the standard therapy alongside pharmacological treatment and should be considered as first-line treatment. Pulsed-fieldablation (PFA) is a novel ablation modality that involves the application of electrical pulses causing cellular death, with preferential tissue specificity. Aim In this study, we evaluated the safety and efficacy of single-shot PFA in AF patients. Methods Single-center registry of consecutive patients undergoing PVI using the pentaspline PFA catheter (all with CARTO3D system v.7 and high-density mapping), between June 2022 and November 2023. Data on demographics, procedural characteristics, and electrocardiographic recurrence (assessed after a 3-month blanking period) were analyzed. Results 152 consecutive patients were included (63 ± 10 years, 57% male), with a mean CHA2DS2-VASc score of 2±1 points, median LVEF of 60% (IQR 59-65%), and a median CT-scan derived left atrial volume index of 56 mL/m2(IQR 44-69 mL/m2). A total of 40% had non-paroxysmal AF and a redo procedure was performed in 17% of patients. The median procedure time was 78 min (IQR 58-111 min) and fluoroscopy time was 11.6 min (IQR 8.2-15.6 min). Additionally, posterior wall isolation (PWI) was performed in 63 patients (41%). There were no esophageal complications, phrenic nerve injuries, cerebrovascular events, or procedure-related deaths. Two patients (1.3%) experienced acute cardiac tamponade, immediately treated with pericardiocentesis. Other complications were primarily vascular, in 5% of cases (4 femoral hematomas, 3 femoral pseudoaneurysms, 1 arteriovenous fistula). Over 293 (IQR 170 - 394) days of follow-up, considering electrocardiographic recurrence, 12% of patients had AF recurrence (5 with paroxysmal AF and 10 with persistent AF). These patients were older (69 ± 7y vs. 62 ± 11y, p=0.016), were more likely to undergo a redo procedure (33 vs. 8%, p=0.004), and had a higher percentage of posterior wall isolation (21 vs. 8%, p=0.038). Conclusions PFA for PVI wall ablation is safe and effective, with 100% intraprocedural technical success, a low rate of complications, and a high percentage of patients free from AF in the short-term.

Left atrial appendage volume estimated by artificial intelligence predicts atrial fibrillation recurrence after cryobaloon ablation

Abstract Background/Introduction The volume of the left atrial appendage (LAA), as measured in contrast-enhanced cardiac computed tomography (CCTA), has been previously reported as a predictor of long-term recurrence of atrial fibrillation (AF) following cryoballoon ablation procedures. Unfortunately manual assessment of LAA volume, is tedious and time-consuming, making it impractical for clinical practice. The recent advent of artificial intelligence (AI)-based methods offers a potential solution to this limitation. Purpose This study aims to evaluate the utility of LAA volume, as automatically measured by a state-of-the-art AI model for the fully automatic segmentation of LAA in CCTA, in predicting AF recurrence following cryoballoon ablation procedures. Methods We retrospectively analyzed a cohort of patients who underwent cryoballoon ablation for pulmonary vein isolation at our facility between 2010 and 2016. AF recurrence was determined through in-person visits and Holter monitoring at 3, 6, and 12 months post-ablation, followed by annual visits. The first three months post-ablation were considered a blanking period. An open-source deep neural network AI model [1] was utilized to perform automatic segmentation and calculation of LAA and left atrium (LA) volumes in. Receiver-operating characteristic curves were used to obtain optimal cut-off values for increased LAA and LA volumes. We then assessed the association of increased LAA and LA volume, and the LAA to LA volume ratio with recurrence-free survival using the Cox regression model. Results The cohort consisted of 212 patients (median age 62, inter-quartile range [IQR]: 55–65), with 25% having persistent AF before the procedure. Subjects were observed for a median period of 12 months (IQR: 12–36), with 70 of them (33%) experiencing a documented recurrent AF episode. The optimal thresholds for predicting AF recurrence were established as 9.8ml for LAA volume, 124ml for LA volume, and 0.086 for the LAA to LA volume ratio, respectively. An increased LAA volume demonstrated the strongest association with AF recurrence (hazard ratio [HR]: 2.6, 95% confidence interval [CI]: 1.55–4.2), followed by an increased LA volume (HR: 2.1, 95% CI: 1.3–3.4), persistence of AF (HR: 2, 95% CI: 1.2–3.3), and increased LAA to LA volume ratio (HR: 1.9, 95% CI: 1.1–3). Kaplan-Meier plots illustrating AF-free survival, are presented in Figure 1. After adjusting for age, persistent AF, left ventricular ejection fraction, and body surface area, all AI measurements remained significantly associated with a higher AF recurrence (Table 1). Conclusions Increased LAA volume, as assessed automatically by AI in CCTA, is a useful predictor of AF recurrence after catheter ablation for atrial fibrillation. The use of freely available, AI-assisted analysis of CCTA could be instrumental in assessing LAA volume, among other predictors, for long-term ablation success.Figure 1.

Long-term efficacy and safety of ablation for atrial fibrillation in patients with hypertrophic cardiomyopathy

Abstract Background Hypertrophic cardiomyopathy (HCM) is often accompanied by atrial fibrillation (AF) but data on safety and long-term outcomes after catheter ablation for AF in HCM are scarce. Purpose To investigate safety, long-term efficacy and clinical outcomes following AF ablation in patients with HCM and in matched controls. Methods Patients with HCM (n=76) undergoing a first catheter ablation for AF or atrial flutter between 1999 and 2022 at a University Hospital in Sweden were included (age 64±12 years, 43% female). Diagnosis of HCM was based on the European Society of Cardiology definition (left ventricular wall thickness ≥15 mm or ≥13 mm not solely explained by abnormal loading conditions, and combined with family history, genetic components and/or electrocardiogram abnormalities). Patients with HCM were matched with controls (n=152) based on age, gender, ablation type and intervention-year. Patients were followed for a mean of 5 years and study endpoints included heart failure hospitalization (HFH), stroke and mortality. Cox regression analyses were performed for the association between HCM and the endpoints. Results Among the overall population, 121 (53%) underwent pulmonary vein isolation (PVI), 62 (27%) isthmus ablation and 45 (20%) His-Bundle ablation. Patients with HCM had a shorter mean duration of AF before ablation (48 months vs. 66 months; p=0.047) and more severe symptoms as indicated by a higher EHRA class (EHRA class IV: 30% vs. 10%; p<0.01). Procedural success rate of PVI and isthmus ablation was lower in patients with versus without HCM (88% vs. 97%; p=0.02). Procedure related complications (vascular complications, tamponade) were overall similar in both groups (9% in HCM vs. 5% in controls, p=0.17) except for higher rates of pulmonary oedema in patients with HCM (7% vs 1%, p=0.03). There was a nearly two-fold increase in risk of AF recurrence after PVI or isthmus ablation in patients with HCM compared to controls (OR 1.95; 95% CI 1.06-3.58; p=0.03). During follow-up, patients with HCM had an increased risk of HFH (HR 2.55, 95% CI 1.21-5.36, p=0.01) but not of stroke or mortality (Figure 1). Conclusion AF ablation was overall safe in patients with HCM but less effective. Patients with HCM had an increased risk of the individual endpoint of HFH after AF ablation but not stroke or mortality during long-term follow-up.

Effects of atrial fibrillation ablation on arrhythmia burden and ventricular function in end-stage heart failure: Lessons from CASTLE-HTx.

The CASTLE-HTx trial showed the benefit of atrial fibrillation (AF) ablation compared to medical therapy in decreasing mortality, need for left ventricular assist device implantation or heart transplantation (HTx) in patients with end-stage heart failure (HF). Herein we describe the effects of catheter ablation on AF burden, arrhythmia recurrences, and ventricular function in end-stage HF. The CASTLE-HTx protocol randomized 194 patients in end-stage HF with AF to catheter ablation and medical therapy or medical therapy alone. AF burden, left ventricular ejection fraction (LVEF), and type of AF were assessed at baseline and at each follow-up visit. Overall, 97 patients received ablation; 66 patients (68%) underwent pulmonary vein isolation (PVI) and 31 patients (32%) were treated with PVI and additional ablation. Electroanatomic mapping showed the extent of left atrial low voltage (cardiomyopathy) >10% in 31 (31.9%) patients. At 12 months post-ablation, persistent AF was present in 31/89 patients (34.8%), which was significantly less frequent compared to baseline (p = 0.0001). Median AF burden reduction was 36.3 (interquartile range 13.6-63.3) percentage points at 12 months and LVEF improved from 29.2 ± 6.2% to 39.1 ± 8.3% (p < 0.001) following ablation. AF burden reduction <50% was significantly associated with LVEF improvement ≥5% at 12 months after ablation (p = 0.017). Atrial fibrillation ablation in end-stage HF leads to a substantial decrease in AF burden, a regression from persistent to paroxysmal AF and notably improved LVEF. Favourable ablation outcomes were observed in patients regardless of the presence or absence of signs indicating left atrial cardiomyopathy.

Procedural Characteristics, Safety and Clinical Outcomes of Pulsed-field Ablation for Pulmonary Vein Isolation in Patients with a Left Common Pulmonary Vein

Procedural Characteristics, Safety and Clinical Outcomes of Pulsed-field Ablation for Pulmonary Vein Isolation in Patients with a Left Common Pulmonary Vein

Neural network reconstruction of the left atrium using sparse catheter paths.

Catheter-based radiofrequency ablation for pulmonary vein isolation has become the first line of treatment for atrial fibrillation in recent years. This requires a rather accurate map of the left atrial sub-endocardial surface including the ostia of the pulmonary veins, which requires dense sampling of the surface and currently takes more than 10min. The focus of this work is to provide left atrial visualization early in the procedure to ease procedure complexity and enable further workflows, such as using catheters that have difficulty sampling the surface. We propose a dense encoder-decoder network with a novel regularization term to reconstruct the shape of the left atrium from partial data which is derived from simple catheter maneuvers. To train the network, we acquire a large dataset of 3D atria shapes and generate corresponding catheter trajectories, from which traversed point clouds are obtained. Once trained, we show that the suggested network can sufficiently approximate the atrium shape based on a given trajectory. We compare several network solutions for the 3D atrium reconstruction. We demonstrate that the solution proposed produces realistic visualization using partial acquisition within a 3-min time interval using human clinical cases.

Electrophysiology lab efficiency using cryoballoon for pulmonary vein isolation in Latin America: A sub-analysis of the Cryo Global Registry Study.

Cryoballoon ablation for pulmonary vein isolation is a time-efficient procedure that can alleviate stress on electrophysiology lab resources. This analysis modeled the impact of cryoballoon ablation on electrophysiology lab operation using data from Latin America. Data from centers in Argentina, Mexico, Colombia, and Chile of the were used as inputs for an electrophysiology lab efficiency simulation model. The model used the assumption that either two (today's electrophysiology lab operations) or three (including electrophysiology lab operational changes) cryoballoon ablation procedures could be performed per day. The endpoints were the percentage of days that resulted in 1) overtime and 2) time left for an extra non-ablation electrophysiology procedure. Data from a total of 232 procedures from six Latin American centers were included in the analysis. The average electrophysiology lab occupancy time for all procedures in Latin America was 132 ± 62 minutes. In the Current Scenario (two procedures per day), 7.4% of simulated days resulted in overtime, and 81.4% had enough time for an extra electrophysiology procedure. In the Enhanced Productivity Scenario (three procedures per day), 16.4% of days used overtime, while 67.4% allowed time for an extra non-ablation electrophysiology procedure. Using real-world, Latin American-specific data, we found that with operational changes, three ablation procedures could feasibly be performed daily, leaving time for an extra electrophysiology procedure on more than half of days. Thus, use of cryoballoon ablation is an effective tool to enhance electrophysiology lab efficiency in resource-constrained regions such as Latin America.

Incidental ablation of ganglionated plexus during atrial fibrillation ablation.

Cardioneuroablation targeting the autonomic nerves within ganglionated plexus (GP) has been used to treat atrial fibrillation (AF). Incidental cardioneuroablation may be an important mechanism by which pulmonary vein isolation (PVI) is effective. Automated fractionation mapping software can identify regions of fractionation correlating with GP locations. To examine the overlap between standard PVI ablation lesions and fractionated electrograms suggestive of GP. We retrospectively examined AF ablations performed from 2021 to 2023 that included only PVI performed using wide antral circumferential isolation without prospective evaluation of fractionation. Retrospectively, a fractionation map was created (width 10 ms, refractory time 30 ms, roving sensitivity 0.1 mv, and threshold of 2). We evaluated the anatomic overlap between PVI lesions and fractionation in regions associated with GP. Among 52 patients (mean 65 (IQR 46-74) years, 82% male, and 69% paroxysmal AF), sites of fractionation corresponding to GP locations were seen in all cases. PVI ablation incidentally overlapped with fractionation in 50 (96%) patients. On average, 26% of the fractionation corresponding with GP locations were incidentally ablated. The highest proportion of fractionated areas were ablated in the left superior (36%) and right superior (31%) GP regions. More complete incidental ablation of these regions was associated with a greater intraprocedural increase in heart rate (ρ = 0.46, p < 0.001), which was subsequently associated with freedom from AF during 15.9 ± 5.2 months of follow-up. Patients undergoing AF ablation universally have fractionated electrograms corresponding to anticipated sites of GP. Partial ablation of these regions frequently occurs incidentally during PVI.

The Feasibility, Safety and Outcome of Very High-Power Short Duration Radiofrequency Ablation in Pulmonary Vein Isolation: A Real-World Observation Study.

Pulmonary vein isolation (PVI) ablation is the established gold standard therapy for patients with symptomatic drug refractory atrial fibrillation (AF). Advancements in radiofrequency (RF) ablation, have led to the development of the novel contact force-sensing temperature-controlled very high-power short-duration (vHPSD) RF ablation. This setting delivers 90 W for up to 4 seconds with a constant irrigation flow rate of 8 mL/min. The aim of this study was to compare procedural outcomes and safety with conventional radiofrequency ablation. An observational study was conducted with patients who underwent first time PVI ablation between August 2020 and January 2022. The cohort was divided into: (1) vHPSD ablation; (2) High-power short duration (HPSD) ablation; (3) THERMOCOOL SMARTTOUCH™ SF (STSF). The vHPSD ablation group was prospectively recruited while the HPSD and STSF group were retrospectively collected. Primary outcomes were procedural success, PVI duration, ablation duration and incidence of perioperative adverse events. Secondary outcomes were intraprocedural morphine and midazolam requirement. A total of 175 patients were included in the study with 100, 30 and 45 patients in the vHPSD, HPSD and STSF group, respectively. PVI was successfully attained in all vHPSD patients. vHPSD demonstrated significantly reduced time required for PVI and total energy application in comparison to the HPSD and STSF groups (67.7 29.7 vs. 92.9 25.7 vs. 93.6 29.1 min, p 0.0001; 9.87 4.16 vs. 33.9 7.49 vs. 36.0 10.5 min, p 0.0001, respectively). Intravenous morphine and midazolam requirement was lower in the vHPSD group compared to the HPSD and STSF groups (10.2 3.43 vs. 16.1 4.58 vs. 15.3 3.94 mg, p 0.0001; 4.04 3.24 vs. 8.63 5.22 vs. 8.58 4.72 mg, p 0.0001). One cardiac tamponade was observed in both the vHPSD and HPSD groups while the STSF group exhibited an embolic stoke and two pericardial effusions that did not require drainage. In this study, vHPSD demonstrated a comparable safety profile to the other treatment arms. Procedural duration and energy application time was substantially reduced along with sedation requirement notwithstanding the limitations of observational study design, these preliminary findings are promising with respect to periprocedural outcomes and safety of vHPSD however longitudinal outcomes will be essential to assessing the overall efficacy of this novel technology.

Impact of different energy sources on coagulation biomarkers and silent cerebral events in balloon-based ablation for atrial fibrillation

BackgroundDifferent energy sources of balloon-based ablation for pulmonary vein isolation (PVI) cause different kinds of endothelial damage and coagulation responses associated with thromboembolic risk. ObjectivesTo compare the impact of different balloon-based ablation, cryo-balloon ablation (CBA) and laser balloon ablation (LBA), on coagulation/fibrinolysis biomarkers and silent cerebral events (SCEs) in paroxysmal atrial fibrillation (PAF). MethodsPAF patients who underwent PVI using either CBA (n=52) or LBA (n=53) without radiofrequency touch-up ablation were eligible. Time-course (day-0 [before ablation], day-1, day-2, and day-28) of myocardial enzymes and inflammatory and coagulation/fibrinolysis biomarkers was evaluated during the perioperative period. Brain MRI was performed within 2 days after the procedure to evaluate SCEs. ResultsThere was no difference in patient characteristics between CBA and LBA.CBA had greater myocardial injury (troponin-I and creatine kinase MB) and lower inflammatory reaction (WBC and neutrophil/lymphocyte ratio) than LBA. The coagulation biomarkers maximally increased by day-2 and then decreased in both groups. In day-28, the serum prothrombin fragment 1+2 and D-dimer levels in LBA were significantly higher than the values in CBA. The fibrinolysis biomarker (plasmin-α2 plasmin inhibitor complex) did not increase after the procedure in either group. The incidence of SCEs was comparable between CBA and LBA (11% vs. 15%, p=0.591). No thromboembolic event was observed. ConclusionCBA and LBA had different effects on myocardial injury, inflammatory reaction, and coagulation activity but did not affect the incidence of thromboembolic events. LBA had significantly higher coagulation activity in day-28 and may require more careful post-procedural anticoagulation than CBA.

Evaluation of left atrial function and tissue after pulmonary vein isolation - initial results of The EVALUATE-PVI STUDY

Abstract Background Pulmonary vein (PV) isolation (PVI) by catheter ablation is a well-established treatment for atrial fibrillation (AF). Currently, the direct and long-term impact of ablation injury on left atrial (LA) function and tissue is poorly understood. Purpose The aim of this study is to evaluate the acute and long-term impact of radiofrequency (RF) PVI ablation on LA function and corresponding tissue changes as assessed with cardiac magnetic resonance imaging (CMR). Methods Seventeen patients (76.5% male, 60.8±9.7 years) with AF who underwent primo RF PVI as part of the EVALUATE-PVI STUDY underwent three sequential CMR scans prior to PVI, and &amp;lt;72 hours and 3 months after PVI ablation. T2-weighted turbo spin echo imaging was applied to assess post-ablation edema. High-resolution three-dimensional (3D) late gadolinium-enhancement (LGE) images were acquired to study acute LA wall injury and chronic fibrosis formation. LA volume and function were derived from two-chamber and four-chamber SSFP cine images. Maximum and minimal LA volume was indexed to body surface area to compute LAVimax and LAVimin. Longitudinal LA strain was calculated using feature tracking, and subdivided into reservoir, conduit, and contractile strain. Results Acutely post-PVI, T2w images showed increased signal intensity and thickening throughout the entire LA wall. LGE images showed diffuse increased signal intensity, without distinct focal high signal intensity areas (Fig. 1). Functional assessment at this stage showed significantly reduced LA emptying fraction (EF), LA reservoir, and contractile strain compared to pre-PVI (54.8±11.1% vs. 48.5±7.9%, p=0.01; 18.6±5.6% vs. 14.6±2.0%, p&amp;lt;0.01; 8.5±3.5% vs. 5.2±1.8%, p&amp;lt;0.001, respectively), while LA conduit strain, LAVimin, and LAVimax did not differ significantly (Fig. 2). The LGE images acquired at 3 months, displayed clear, focal, high signal intensity areas surrounding the PVs. At this stage post-PVI, a significant increase in LA strain was observed (LA reservoir strain 14.6±2.0% vs. 16.9±3.5%, p&amp;lt;0.01; and contractile strain 5.2±1.8% vs. 6.7±2.9%, p&amp;lt;0.01; respectively). LAVimax was significantly reduced at 3 months compared to acutely post-PVI (Fig. 2). LAVimin and LA conduit strain did not differ between the pre- and post-PVI stages. Conclusion PVI ablation resulted in temporary reduced LA function acutely post-PVI, likely due to edema and thickening of the LA wall. At three months, LGE images revealed clearly visible increased signal intensity in the ablated segments. At this stage, LA function improved, though full recovery did not occur as evidenced by the persistent slightly reduced contractile strain, possibly due to the ablation-induced loss of LA myocardium and formation of fibrosis. The decrease in LAVimax indicates reverse remodeling as a result of the ablation.

Ten-year follow-up results of patients with persistent atrial fibrillation treated by combined pulmonary vein isolation and complex fractionated atrial electrocardiogram ablation

Abstract Background For persistent atrial fibrillation (AF), pulmonary vein isolation (PVI) alone is associated with lower success rate compared to paroxysmal AF and additional strategies are needed. Ablation targeting on complex fractionated atrial electrograms (CFAE) is an alternative method. Although clinical benefits of the strategy combined PVI and CFAE ablation have not been shown by large trials, clinical situations and consequences of this approach have not been clearly demonstrated during very long term follow-up. Purpose This study aimed to retrospectively investigate clinical outcomes of patients with persistent AF treated by the approach combined PVI and CFAE ablation during a follow-up period of 10 years. Methods 73 patients (59.4±8.1 years, 64 male, AF history 5.5 years) with persistent (23, 31.5%) and long-standing persistent AF (50, 68.5%) who underwent combined PVI and CFAE ablation in the first procedure were included. Structural heart disease was found in 9 patients, and a history of ablation for typical atrial flutter (AFL) in 4. A complete CFAE mapping in the left atrium and coronary sinus was performed with a 3-D mapping system (EnSite NavX). All CFAEs defined as electrograms with continuous activities or mean cycle length detected by the system &amp;lt;80 ms were eliminated. All patients were controlled regularly during the first year with 12-lead ECG and Holter monitoring and followed by annual control. The electronic health records for all patients were extensively investigated and the patients were interviewed in 2020-2022. Any documented atrial tachyarrhythmia (ATA) after 3-month blanking period was regarded as recurrence. Results Mean 2.2±1.2 (1-5) ablation procedures were performed in each patient. After index ablation, 18 (24.7%) were free of ATAs during 10-year follow-up. 26 (35.6%) had recurrence of only AF, 6 (8.2%) of only AFL and 23 (31.5%) had both AF and AFL. The proportion of AFL was 39.7% with 6 typical AFL. After multiple ablation procedures, 33 (45.2%) patients were free of ATA during the follow-up. 23 (31.5%) had recurrence of only AF, 5 (6.8%) of only AFL and 12 (16.4%) of both AF and AFL. The proportion of AFL was 23.2% with no typical AFL. At 1-year follow-up, freedom of ATAs in persistent AF was higher than that in long-standing AF (65.2 vs. 40.0%, p=0.033) and no significant difference was found after 2 years (47.8 vs. 34.0%, p=0.129) until 10 years (30.4 vs. 22.0%, p=0.167, Figure 1). No difference was observed between these subgroups after multiple procedures at 10-year follow-up (47.8 vs. 44.0%, p=0.708, Figure 2). Conclusions PVI plus CAFE ablation in patients with persistent AF led to a high recurrence of ATA after index ablation. Difference of ATA-freedom between persistent and long-standing persistent AF groups was found only 1 year after the index procedure, but not during further follow-up. Incidence of post-ablation AFL was particularly high, even after multiple ablation procedures.Figure 1Figure 2

Intraprocedural and outcome findings in repeat left atrial procedures after pulsed field ablation for pulmonary vein isolation in paroxysmal and persistent atrial fibrillation

Abstract Background Pulsed Field Ablation (PFA) has emerged as a promising novel technique for pulmonary vein isolation (PVI) in the setting of atrial fibrillation. First outcome data revealed comparable success rates to radiofrequency and cryoablation. However, data on lesion dimensions and reconnection of PV after PFA potentially causing recurrence of AF is sparse. We, therefore report on pivotal reconnection sites and ablation extend after PFA-PVI. Methods All patients after PFA-PVI for paroxysmal or persistent AF at our center between September 2021 and October 2023 were included in this retrospective analysis. Baseline characteristics, procedural and outcome data were obtained. Furthermore, in all redo procedures of these patients lesion dimensions and the occurrence and location of PV gaps were evaluated. Results A total of 123 patients with atrial fibrillation underwent successful PFA-PVI during index procedure. The study cohort comprised [n= 52; 42%] paroxysmal and [n= 71; 58%] persistent atrial fibrillation cases. After a median follow-up of 123 (IQR 93-150) days recurrence of atrial arrhythmia (all AF) occurred in 9 [14. 5%] patients. Of these, 6 [9.6%] patients underwent a redo procedure due to recurrence of atrial fibrillation (3 PAF and 3 persAF [50%]; p=1). All left atrial maps and 24 PVs were analyzed. All 6 [100%] patients exhibited electrical reconnection of one or more pulmonary vein. Analysis of redo procedures revealed that the dimensions of PFA-induced lesions varied among patients: The right inferior pulmonary vein (RIPV) showed reconnection in all redo-patients (100%). Also frequent reconnection was observed for the RSPV (3 pts [50%]) and LIPV (2 pts [33%]). The gap size was 66±40% of the circumference in the reconnected RPVs and 61±31% in the reconnected LPVs. A roof-line lesion set was performed in 4 out of 6 pts (67%) due to the initially antral PV lesions affecting the posterior wall and LA roof potentially creating an isthmus for roof-dependent atrial tachycardia (AT). Conclusion Outcome data for PFA-PVI are comparable to other energy sources used for PVI. However, reconnection of PV also occurs after PFA-PVI. This retrospective analysis of redo procedures after initially successful PVI identified the RIPV as pivotal for reconnection. Furthermore, map analysis revealed that reconnection gaps extend to up to 2/3 of the initial circumferential PV ablation area. Furthermore, PFA seems to create new critical isthmuses potentially causing AT. No difference in reconnection was seen comparing PAF and persAF.

First comparison of single-tip versus single-shot pulsed field ablation for pulmonary vein isolation in paroxysmal atrial fibrillation: interim analysis of a randomized trial

Abstract Background Non-thermal pulsed field ablation (PFA) is an emerging technology to perform pulmonary vein isolation (PVI) for atrial fibrillation (AF). Different PFA systems are available, but no comparative data exist. Purpose Randomized trial to compare single-tip versus single-shot PFA for initial PVI in paroxysmal AF patients. Methods In this single-center trial, paroxysmal AF patients are prospectively enrolled and 1:1 randomized in the single-tip or single-shot PFA group. Single-tip PVI is performed using a PFA generator and a 3.5mm contact-force enabled ablation catheter guided by 3D mapping system. The pulsed electric field dosing is 25 Ampere (A) (anterior) and 22 A (posterior), respectively. In the single-shot PVI group, a 31 or 35mm pentaspline PFA catheter is used for fluoroscopy-guided PVI. Eight PFA applications (2.0 kV) are applied per PV. In this interim analysis, acute efficacy, safety and short term clinical outcome within the 3 months blanking period were assessed. A subset of patients underwent cerebral MRI to detect silent lesions. Results To date, 50 patients were enrolled and underwent PVI in conscious sedation (25 single-tip, 25 single-shot, 63 ± 5 years, 42% female, CHA2DS2-VASc 2 [1-3]). There were no differences in baseline characteristics. Acute PVI was achieved in 100%. In the single-tip group, total procedure time was significantly longer (125 ± 31 min vs. 44 ± 12 min, p &amp;lt;0.001) and fluoroscopy time was significantly shorter (4 ± 2 min vs. 15 ± 6 min, p &amp;lt;0.001) as compared to the single-shot group. One groin hematoma was noted in the single-shot group. In the single-tip group, 1 aneurysm spurium was detected and 1 pericardial tamponade requiring drainage resulted from coughing during single-tip PFA while no real-time visualization of the catheter was available. No permanent sequelae occurred. There were no PFA specific complications and no cerebral embolisms were detected in all 14 MRI scans. At 3 months, 92% (single-shot group) and 80% in the single-tip group were free from arrhythmia (p=0.42). AF recurrences in the blanking period occurred in 2 patients in the single-shot group and in 5 patients in the single-tip group after a median of 2 [1-5] days following the procedure. Conclusions In this interim analysis of a randomized trial, single-shot or single-tip PFA for PVI both demonstrated high acute efficacy and a favourable 3 months clinical outcome. Procedural time was significantly longer in the single-tip PFA group. No silent lesions were detected in cerebral MRI. Non-availability of real-time visualization and contact-force information of the single-tip ablation catheter during energy application is a current technical limitation that could be associated with complications.

Ultra-high density mapping for the evaluation of the antral scar extension after ablation with a radiofrequency balloon catheter in atrial fibrillation patients

Abstract Background The Heliostar radiofrequency (RF) balloon ablation catheter enables one-shot pulmonary veins isolation (PVI). The RF balloon by occluding the PV ostia creates an antral scar. Purpose We sought to investigate the extension of the antral scar by mean of ultra-high density mapping. Methods Paroxysmal and persistent atrial fibrillation (AF) patients undergoing first PVI ablation with the Heliostar catheter across 4 European centers were enrolled. Ultra-high density mapping of left atrium was performed with the Octaray catheter, a octa-spline mapping catheter before and after the ablation. All maps were acquired in sinus rhythm, patients in AF underwent electrical cardioversion before mapping. The bipolar voltage maps from each patients were analysed: the left atrial area &amp;lt; 0.2 mV was considered scar and was calculated before and after the ablation and the distance between left and right antral lesions at upper and inferior posterior wall were also calculated. Results Overall, 49 patients were enrolled, 82% were male, the mean age was 60±9 years, 66% had paroxysmal AF. PVI was achieved in 100% patients. The mean left atrial area was 209±44 cm2, the scar after the ablation was 9±4.6 %, with 49±11% of the posterior wall still viable (bipolar voltage &amp;gt; 0.5mV). The distance between left and right antral lesions at the upper posterior wall was 26.57 mm whereas at the inferior aspect was 29.59 mm. Conclusions The RF balloon catheter creates a wide antral scar during AF ablation although without compromising the integrity of the posterior wall.

Posterior wall isolation with pulsed field ablation or radiofrequency ablation with vein of marshall ethanol ablation for the treatment of atrial fibrillation

Abstract Background In patients undergoing repeat catheter ablation for atrial fibrillation (AF) two ablation strategies beyond pulmonary vein isolation (PVI) have recently gained increased interest: posterior wall isolation (PWI) using pulsed field ablation (PFA) and Vein of Marshall (VoM) ethanol ablation combined with radiofrequency energy ablation (RFA). However, a direct comparison is lacking. Purpose To compare prospectively enrolled patients undergoing repeat catheter ablation for persistent AF using PVI and PWI with PFA (PFA group) vs. PVI and VoM ethanol ablation using RFA (VoM group) regarding procedural characteristics, safety, myocardial injury and outcomes. Methods Patients undergoing redo PFA-PVI with PWI and VoM ethanol ablation with RFA were included. Isolation and bidirectional block were checked using a multipolar mapping catheter. High-sensitivity cardiac troponin T (hs-cTnT) was measured after 24h of ablation. Results A total of 84 patients were included (age 69 [interquartile range (IQR) 63-75] years; ejection fraction 56% [IQR 48-60%]; left atrial size 42 [IQR 37-47] mm), baseline characteristics did not differ significantly between groups. Of these, 54 patients (64%) were in the PFA group and 30 (36%) in the VoM group. The procedure duration (65 [IQR 56-73] minutes vs 116 [IQR 103-142] minutes; p &amp;lt; .001) and fluoroscopic times (11 [IQR 8–14] minutes vs 14 [IQR 12-19] minutes; p &amp;lt; .001) were significantly shorter for the PFA group than for the VoM group. No major complications were observed except for a probable allergic reaction in the VoM group and a transient AV-block in the PFA group. High-sensitivity cardiac troponin levels post ablation were similar between the PFA group and the VoM group with 886 [IQR 627–1260] ng/L and 793 [IQR 543-1199] ng/L, p=0.28, respectively. During follow-up (median duration 230 [IQR 117-370] days), AF recurrence was observed in 15% in the PFA group and in 40% in the VOM group (p ≤ 0.01). Conclusion In patients undergoing repeat catheter ablation for AF, PVI and PWI using PFA is associated with shorter procedure and fluoroscopic times, similar high-sensitivity cardiac troponin levels and a reduced recurrence rate compared to PVI using RFA with additional VoM ethanol ablation.Central Illustration

Long-term success and predictors of atrial arrhythmia recurrence following left atrial flutter ablation

Abstract Background In recent years, success rate of left atrial flutter (LAFL) ablation has witnessed improvement, attributed to enhanced comprehension of the arrhythmia mechanism and technological advancements. However, the recurrence rate and specific types of atrial arrhythmias, along with their potential predictors, remain inadequately understood. Purpose The aim of this study is to assess the factors influencing the efficacy, safety, and long-term success of radiofrequency (RF) ablation for LAFL. Methods Patients with sustained LAFL undergoing RF ablation were included in the study. LAFL mapping employed a combination of activation, voltage, and entrainment with 3D electroanatomical mapping. RF ablation targeted a protected isthmus of slow conduction, and if not localized, it involved creating lines of conduction block transecting the reentrant circuit or empirically created lines. Ablation success was defined as clean arrhythmia termination during RF application and no LAFL induction with pacing maneuvers. Follow-up included outpatient visits at 6 and 12 months. Ablation success at follow-up was defined as the absence of arrhythmia recurrence (≥30s) at regular outpatient or emergency department visits. Clinical and electrophysiological characteristics were analyzed and correlated with ablation success, complications, and freedom from arrhythmia recurrences at follow-up. Results The study included 104 consecutive patients undergoing LAFL ablation (67.5 ± 11.3 years, 67% male). Clinical characteristics comprised 12 with HFrEF, 44 with structural heart disease, 25 with valvular heart disease, 43 with previous pulmonary vein isolation (PVI) ablation, and 39 with significant left atrium enlargement. Simultaneous cavotricuspid isthmus ablation (CTI) was performed in 46 patients. LAFL cycle length was 293±68 ms, with more than one LAFL mechanism (2.0±0.8 mechanisms) demonstrated in 76 patients (73%). The most common LAFL mechanism was perimetral reentry (37%). LAFL was successfully ablated 83% of cases, with 7 patients experiencing complications (4 tamponades and 3 sinus node dysfunctions following LAFL termination). At a median follow-up of 28 months, 35 patients (34%) had AFL recurrence, and 15 of them required a second ablation procedure. No factor was associated with LAFL recurrence, except for a short LAFL cycle length (P=0.04) at the ablation procedure. Demonstration of more than one LAFL mechanism (P=0.48) or LAFL termination by focal or linear RF application (P=0.99) were not associated with AFL recurrences at follow-up. Conclusions Despite the relatively high efficacy of LAFL ablation, the rate of atrial arrhythmia recurrences at follow-up after a single procedure remains elevated, predominantly in the form of AFL rather than AF. Short LAFL cycle length at the index procedure appears to be a significant predictor of these recurrences. Arrythmia cycle length proved to be predictive factor of LAFL ablation success rate.Peri-veinal left AFL, LAT map, CranialPeri-veinal left AFL, LAT map, PA

Patient-tailored low-voltage-guided ablation of atrial fibrillation: initial experience using a novel ultra-low-temperature cryoablation system

Abstract Introduction The ideal ablation strategy for patients (pts) with persistent atrial fibrillation (PersAF) is still debated. In recent randomized studies, strategies of ablating electrically abnormal atrial regions in addition to pulmonary vein isolation (PVI) have shown promise, and a novel ultra-low-temperature cryoablation (ULTC) system might overcome the limitations of radiofrequency (RF) energy to create transmural lesions in diseased tissue. Purpose Aim of this study is to report procedural aspects, acute efficacy, and safety of our initial experience in treating AF pts with this novel ULTC system. Methods Patients scheduled for catheter ablation who had a high likelihood of having left atrial (LA) low voltage zones (LVZ) underwent ablation with the ULTC system. A detailed high-density LA 3D-electronatomical map was created in sinus rhythm using a multi-electrode catheter. Bipolar LVZs were defined as at least 1cm2 surface of bipolar voltage &amp;lt;0.5mV. The ablation strategy consisted of PVI and linear ablation of the LVZs, transecting (if narrow) or isolating (if broad) the areas of abnormal signals and anchoring these lines to electrically silent structures (PVs or mitral valve ring). Electrical isolation and block across linear ablations were tested as universally accepted. Continuous variables are expressed as median (and interquartile ranges). Results From April to September 2023, 25 pts (10 female) were included (see table for patients´ and procedural characteristics). Procedure duration was 210 (135-270) min, and diminished over time from initially (in the first 12 pts) 260 (203.75-302.50) min to 190 (135-235) min (p=0.047). PVI was achieved in 15/18 pts (83%) using the ULTC, in the remaining 3 pts RF energy touch-up was needed. Linear ablation and isolation of LVZs were always (41/41 in 22pts, 100%) successfully achieved with the ULTC (see figure for an example). Except for 1 right phrenic nerve palsy, no major acute complications were observed. Post-procedural chest pain was not reported by any patient, in 1 patient mild pericardial effusion was detected and treated conservatively. During the 48h post-procedural ECG-monitoring, no sustained atrial arrhythmias occurred. Conclusions This is the first report of patient-tailored low-voltage-guided AF-ablation using a novel ULTC system. Despite representing our initial clinical experience, acute efficacy was very good (95% of acute bidirectional block across lines). Procedure-duration decreased over time, indicating an initial learning curve. Acute safety was reassuring but particular attention should be paid for phrenic nerve function during ablation of the right PVs. The absence of post-procedural pain, pericardial effusion, or acute post-procedural arrhythmias indicates limited ablation-induced inflammation.Result of ULTC ablation in a diseased LA

Electrophysiological characteristics and durability of index pulsed field ablation lesions from redo procedures for atrial arrhythmia recurrences

Abstract Background Catheter ablation for atrial fibrillation (AF) has been performed using mainly thermal energy sources (radiofrequency, cryo, or laser). Pulsed field ablation (PFA) is a novel energy with interesting safety and effectiveness demonstrated in previous preclinical and clinical trials. Purpose We sought to assess the electrophysiological characteristics and durability of PFA index procedure procedures using a pentaspline PFA catheter as assessed based on redo procedures in patients with AT/AF recurrences. Methods A total of 169 patients (paroxysmal AF (PAF), 120; persistent AF (PsAF), 49) who underwent PFA using a pentaspline PFA catheter in the index procedure from November 2021 to July 2023 were studied. Pulmonary vein isolation (PVI) was performed with PFA in all patients with additional PFA lines: i)posterolateral mitral isthmus (MI) ablation in 25, ii) posterior line in 40 patients. Twenty-seven patients (PAF, 11; PsAF, 16) had atrial arrhythmia (atrial tachycardia (AT) or AF) recurrence after a 3-month blanking period (16%). We analyzed the electrophysiological characteristics of previous PFA lesions in 18 (PAF, 8; PsAF, 10) out of 27 patients in whom an activation and voltage mapping using 3-D electroanatomical mapping system was available. Results PV reconnections were identified in 7 of 18 patients (13PVs/69PVs ,18.8%) at the PV-LA junctions and carina regions of both left PVs and right PVs, mainly at the anterior aspect of right PV carina (n=6). In 6 out of 10 redo cases, posterolateral MI line using PFA was performed in the index procedure based on our strategy for PsAF ablation. In these 6 cases with previous MI line using PFA for PsAF ablation endocardial PFA was combined with marshall vein ethanolization(Et-VOM). Additional RF endocardial ablation and in the CS was needed to achieve MI block in 2 (33%) in the index procedure. 3D mapping of redo cases showed MI line gaps in 6/6 (100%). In 3 of those patients, the clinical arrhythmia recurrence was a perimitral AT (50%). Nine of the 10 PsAF patients who underwent a redo procedure had an index procedure complete posterior line. Remapping demonstrated durable block in 7/9 (78%). One of these patients presented with a roof dependent AT diagnosed in the redo procedure. Durable posterior lines received a significantly larger number of PFA deliveries during the index procedure: 16.4±3.3 vs 10.0±2.8 respectively, p=0.041). Conclusion This study based on redo cases after PFA using a pentaspline PFA catheter shows that PFA is associated with high durability for PVI and posterior line ablation. However the durability of MI line are poor, even when combined with VOM ethanolization. Further research is needed to define the optimal number of deliveries required to achieve durable posterior line block.