Pulsed-field ablation versus thermal ablation for persistent atrial fibrillation: a systematic review and meta-analysis

Funding AcknowledgementsType of funding sources: Private company. Main funding source(s): Boris Schmidt, KR Julian Chun and Stefano Bordignon received speaking honoraria from Medtronic and Boston ScientificBackgroundThe cryoballoon (CB) is one of the most commonly used single shot devices for pulmonary vein isolation in patients with atrial fibrillation (AF). Pulsed field ablation (PFA) is a new non-thermal, tissue selective approach for pulmonary vein isolation.PurposeWe sought to compare procedural safety and efficacy of these single shot ablation techniques.MethodsConsecutive AF patients (paroxysmal / persistent AF) who underwent CB based pulmonary vein isolation (PVI) between November 2020 and February 2022 were enrolled and compared with patients who underwent PFA ablation in the same time period. Patients that underwent ablation beyond PVI (except for cavo-tricuspid isthmus ablation) were excluded. CB PVI was performed using the second-generation CB (CB 28 mm) with 240 sec based freeze protocol and bonus freeze delivery in case of time-to-isolation (TTI) >75 sec. PFA was performed using the Farawave catheter, using the 31 or 35 mm device. All procedures were performed under deep sedation.ResultsData from 400 consecutive patients were collected. Most baseline characteristics like age (CB: 67,5 ± 15,3; PFA: 68,4 ± 11; p=0,49), BMI (CB: 28,6 ± 6,3; PFA: 27,9 ± 5,6; p=0,27) and gender (male) (CB: 54%; PFA: 59%; p=0,31) were comparable between the two groups. All PVIs were successfully completed.In 98% (196) of patients in the CB group and 100% (200) in the PFA group, PVI was performed using solely CB or PFA respectively, meaning additional touch up ablation was only needed in 4 CB patients (2%; p=0,044) and 4 veins.Procedure time was significantly shorter in the PFA group (CB: 53 ± 15,3 minutes; PFA: 36,8 ± 13,5 minutes; p<0,001), whereas no difference in fluoroscopy time (CB: 8,1 ± 4,4 minutes; PFA: 7,8 ± 3,3 minutes; p=0,2) was observed. The rate of concomitant CTI-ablation was equal in both groups (CB: 1,5%; PFA: 1,5%; p=1,0). Complication rate was 3,5% with PFA and 6,5% in CB (p=0,17), a difference mostly driven by persistent phrenic nerve palsies (CB: 1,5%; PFA: 0%; p=0,08).All patients are out of the blanking period. There were 80 recurrences in blanking time (CB: 41; PFA: 39; p=0,8). In CB 19,5% of blanking time recurrences were atrial tachycardias compared to 35,9% in PFA (p=0,1). The average time to blanking recurrence was 14,1 ± 21,5 days in CB and 20,5 ± 23,2 in PFA (p=0,2). In total, there were 7 repeat procedures (4 in CB and 3 in PFA; p=0,7) during blanking time due to arrhythmias, despite of antiarrhythmic drugs and/or cardioversion.At the time of this analysis, the first hundred patients in each group reached one-year follow-up. Recurrence free survival after one year for patients with PAF was 82,6% in CB and 80,0% in PFA. In patients with persistent AF it was 70,8% in CB and 67,8% in PFA.ConclusionCryoballoon and pulsed field ablation are both highly effective and safe techniques for PVI. PFA had a shorter procedure time, whereas the one year follow up was similar for both techniques.Procedural dataProcedural complications

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.

POSTER PRESENTATIONS

Research Needs and Priorities for Catheter Ablation of Atrial Fibrillation

There are sparse high-quality safety and effectiveness data for pulsed field ablation (PFA) of persistent atrial fibrillation (PerAF), in which lesions beyond pulmonary vein isolation (PVI) are often placed. In addition, no large trials have used insertable cardiac monitors for continuous rhythm monitoring after ablation in patients with PerAF or after PFA in any atrial fibrillation population. In Phase 2 of the ADVANTAGE AF study (A Prospective Single Arm Open Label Study of the FARAPULSE Pulsed Field Ablation System in Subjects With Persistent Atrial Fibrillation), patients with PerAF underwent PFA for PVI and posterior wall ablation (PWA) and, in a subcohort, cavotricuspid isthmus ablation for typical atrial flutter. Patients with PerAF underwent PVI and posterior wall ablation with the pentaspline PFA catheter and cavotricuspid isthmus with a novel focal-linear PFA catheter after intravenous nitroglycerin prophylaxis. Patients were followed up for 1 year with continuous rhythm monitoring after ablation with insertable cardiac monitors to emulate traditional intermittent monitoring for the primary efficacy end point and to examine atrial arrhythmia (AA) burden and episode duration. This 255-patient cohort (age, 66.7±9.3 years; female, 29%; CHA2DS2-VASc score, 2.4±1.4; body mass index, 30.9±5.3 kg/m2; left atrium diameter, 4.3±0.6 cm) underwent PVI plus posterior wall ablation (99.6%/100% acute success); a subpopulation (n=141; 55.3%) also received cavotricuspid isthmus PFA, with 98.6% achieving bidirectional block without complications (ST-segment changes, ventricular fibrillation). Cavotricuspid isthmus ablation took 8±13 minutes, using 18±6 pulsed field applications and 4±2 mg IV nitroglycerin. The total procedure and atrial dwell times were 105±36 and 59±24 minutes, respectively. Mimicking traditional monitoring, freedom from AA was 73.4% with adverse events in 2.4%, both meeting prespecified end-point criteria. Freedom from recurrent atrial flutter was 97.2%. Detailed analysis of the full insertable cardiac monitor data revealed freedom from AA of ≥30 seconds in 52.0%, and no episode exceeded 24 hours in 94.0% of this PerAF cohort. Both an AA burden >0.1% and longest episode duration >1 hour were predictive of increased health care use. One-year procedural effectiveness was 71.6% and 70.0% using the thresholds of ≤0.1% burden and <1 hour duration, respectively. In Phase 2 of ADVANTAGE AF, the first multicenter PerAF study of PFA with continuous rhythm monitoring: (1) cavotricuspid isthmus ablation with nitroglycerin prophylaxis was safe and effective, (2) PVI plus posterior wall ablation was safe and effective, and (3) an AA burden <0.1% and AA episode <1 hour duration were end points associated with the lowest health care use. URL: https://www.clinicaltrials.gov; Unique identifier: NCT05443594.

Background Pulsed field ablation (PFA) has emerged as a novel technology that is increasingly applied for the catheter ablation (CA) of atrial fibrillation (AF) with similar efficacy to established, thermal energy sources. Data solely focussing on analgosedation compared to established single-shot modalities, such as cryoballoon (CB) ablation are scarce. Aim The aim of this study was to assess differences of analgosedation requirement, procedural cardiopulmonary stability, and analgosedation-associated complications between PFA and CB ablation. Methods This study was a retrospective single-centre comparison of analgosedation in patients with paroxysmal, persistent, and long-standing persistent AF undergoing pulmonary vein isolation (PVI) with either PFA or CB from March 2021 until April 2022. The primary study endpoints were the requirements of analgosedation medications (propofol, midazolam and sufentanyl), cardiorespiratory stability measured as decreases in oxygen saturation and systolic blood pressure and analgosedation-associated complications. Secondary endpoints were acute procedural success, procedure time and overall complication rates. Results A total of 100 patients were included {PFA n=50, CB n=50, mean age 66 ± 10.6, 61% male patients, 65% paroxysmal AF). The body weight – and procedure time-adjusted requirement of all analgosedation medications was significantly higher in the PFA group compared to CB {Propofol 0.14 ± 0.04 mg/kg/min in PFA versus 0.11 ± 0.04 mg/kg/min in CB (p=0.001); midazolam 0.00086 ± 0.0004 mg/kg/min in PFA versus 0.00063 ± 0.0003 mg/kg/min in CB (p=0.002) and sufentanyl 0.0013 ± 0.0007 µg/kg/min in PFA versus 0.0008 ± 0.0004 µg/kg/min in CB (p&amp;lt;0.0001)}. Procedural cardiorespiratory stability did not differ between groups (maximum blood pressure decrease PFA 53.4 ± 20.9 mmHg, CB 50.3 ± 18.6 mmHg, P=0.28 and maximum decrease in oxygen saturation: PFA group 4.8 ± 5.3 %, CB group 3.5 ± 2.6 %, P=0.12). Analgosedation-associated complications did not differ between both groups (PFA n=1/50 mild aspiration pneumonia, CB n=0/50, p=0.99). There was no significant difference in acute procedural success (100% n=50/50 in both groups, p&amp;gt;0.99), non-analgosedation associated complications (PFA: n=2/50, 4%, CB: n=1/50, 2%, p=0.99) and procedure times (PFA 75 ± 31, CB 84 ± 32 mins, p=0.18) between groups. Conclusions Pulsed field ablation is associated with higher sedation and especially analgesia requirement compared to cryoballoon ablation, however, the safety of analgosedation does not differ significantly to cryoballoon ablation.

BackgroundPulmonary vein isolation (PVI) is a highly effective therapy for treating atrial fibrillation (AF). PVI using non-thermal pulsed field ablation (PFA) has recently shown comparable outcomes to thermal ablation such as cryoballoon ablation (CBA). Single-shot devices such as CBA and by extension PFA offer several advantages, particularly in reducing ablation time, potentially benefitting patients with comorbidities. Despite increasing prevalence of obesity, there is limited data on the optimal PVI method for this patient population.AimThe aim of this study was to compare procedural data, outcome and complication rates of PFA to CBA in obese patients.MethodsAll de novo PVIs performed at our center between September 2021 and June 2023 using PFA and CBA were analysed. Only obese patients (BMI ≥ 30 kg/m²) undergoing de novo PVI were included in this analysis.ResultsA total of 85 PVI procedures were included. 32 (37.6%) patients underwent PFA and 53 (62.4%) patients received CBA. Baseline characteristics were comparable between groups. In the PFA group (65.6% male; mean age 67.7 ± 8.0 years), 68.8% of patients suffered from persistent AF, with an average BMI of 33.3 ± 3.0 kg/m². In the CBA group (73.6% male; mean age 64.3 ± 10.3 years), 47.2% of patients suffered from persistent AF, and the average BMI was 33.0 ± 2.9 kg/m². Procedure time was significantly shorter with PFA compared to CBA (PFA: 57.0 ± 19.7 min; CBA: 64.7 ± 17.3 min; p=0.0167), and the use of contrast medium was significantly lower in the PFA group (PFA: 10.9 ± 8.7 ml; CBA: 47.2 ± 23.0 ml; p<0.0001), while fluoroscopy time (PFA: 12.2 ± 4.2 min; CBA: 11.2 ± 4.2 min, p=0.2) and dose (PFA: 6872.8 ± 11072.8 mGy·cm2; CBA: 7834.5 ± 13419.2 mGy·cm2; p=0.6) were comparable. Major complications in the PFA group were one pericardial tamponade, and two intermittent sinus arrests. In the CBA group one patient experienced a pseudoaneurysm and one patient developed pneumonia due to aspiration (PFA: n=3, 9.4%; cryo: n=2; 3.8%; p=0.3). After a mean follow-up of 310.2 days, 83.3% of patients in the PFA group and 77.4% in the CBA group were free from atrial arrhythmia, with no significant difference in the survival analysis (p=0.6, log-rank HR 0.75, 95% CI 0.28–2.04).ConclusionIn obese patients, PFA is comparably safe and effective to achieve complete PVI with the potentially added benefit of a shorter procedure time and reduced contrast medium usage compared to CBA. However, this study primarily included patients with class one obesity and only few with higher-grade obesity. Risks associated with ablation may increase in patients with higher grade of obesity and PFA might be even more beneficial for these patients.Figure 1:Kaplan-Meier analysis

▪ Abstract Atrial fibrillation is frequently disabling and resistant to antiarrhythmic drugs. Curative treatment by catheter-based ablation has been shown to be feasible either by achieving long linear lesions, mainly in the left atrium, or by targeting the initiating focus, most frequently in the pulmonary veins. This paper reviews the different ablation approaches, their results, potential complications, and relative merits.

BackgroundCatheter ablation (CA) is a key treatment for atrial fibrillation (AF), with international guidelines now endorsing class I indications for its use in various clinical contexts. Pulsed field ablation (PFA) and very high-power short-duration (vHPSD) radiofrequency ablation are recent technologies for AF treatment. However, the procedural performance, safety, and acute effectiveness of PFA compared to vHPSD are not yet well established.ObjectiveThis study aimed to compare PFA with vHPSD for the management of paroxysmal and persistent AF.MethodsWe conducted an observational, single-center study enrolling 90 consecutive patients (mean age 61.9 ± 9.9; 23.3% female) with paroxysmal (n=74) or persistent (n=16) AF. Patients were treated with either a bidirectional, variable loop size (25–35 mm) ablation and mapping PFA catheter (n=45; persistent AF n=8) or a vHPSD catheter with microelectrodes and 6 thermocouples for real-time temperature monitoring during ablation (90 W, 4 seconds; n=45; persistent AF n=8) between 2020 and 2024. Pulmonary vein isolation (PVI) was the primary efficacy endpoint. The primary safety endpoint was a composite of procedure-related complications.ResultsDemographic characteristics were similar between the two groups (Table 1). Successful PVI was achieved in all patients, with shorter procedure durations in the PFA group (68.8 ± 17.9 minutes) compared to vHPSD (113.6 ± 30.6 minutes; p = 0.00054). This difference remained significant after propensity score matching (n=42; PFA, 70 ± 18.1 minutes; vHPSD, 112.8 ± 31.5 minutes; p = 0.000577) and when stratifying by several subgroups, including isolated PVI, PVI plus cavo-tricuspid isthmus (CTI) ablation, paroxysmal AF, persistent AF, and posterior wall ablation (Table 2). Fluoroscopy time was shorter for PFA but not significantly different (PFA, 10.25 ± 5.7 minutes; vHPSD, 11 ± 6.45 minutes; p = 0.56). PFA was associated with more frequent use of general anesthesia (p < 0.0001). Primary safety outcome events occurred in 1 patient (1.1%), with low rates in both groups (PFA, 0%; vHPSD, 2.2%).ConclusionIn this single-center experience, PFA was associated with more frequent use of general anesthesia, shorter procedural times, and similar fluoroscopy exposure compared to vHPSD ablation, with both techniques exhibiting comparable safety and acute efficacy.Table 1:Demographic Characteristics Table 2:Procedural Details

Pentaspline catheter or cryoballoon for pulmonary vein plus posterior wall isolation in persistent atrial fibrillation: 1-Year outcomes.

Pulmonary vein isolation (PVI) remains the cornerstone in the treatment of atrial fibrillation (AF). PVI using cryoballoon (CB) technology has emerged as a standard procedure in many centers. Recently, pulsed field ablation (PFA) has been introduced and used to achieve PVI. First data show high acute and favorable long-term outcomes. So far, data comparing these new "single shot" devices are sparse. We sought to compare procedural and outcome data for first time PFA users versus CB in patients undergoing de novo PVI. Furthermore, potentially postprocedural discomfort and affection of autonomic ganglia were assessed. A retrospective analysis and comparison of all de novo PVIs with PFA and CB was performed. Furthermore, PFA PVI learning curve was evaluated. During follow-up, repeat outpatient visits and Holter electrocardiogram were performed to analyze arrhythmia-free survival. Discomfort analysis was obtained by prescribed analgesic medication within first 48 h after PVI. Potential changes in heart rate (HR) between baseline and at 3-month follow-up were evaluated. A total of 108 patients (54 PFA and 54 CB; PFA; 33 (30%) female) with paroxysmal and persistent AF were analyzed. Type of AF was comparable (Patients suffering from PAF: PFA: 16 (30%), CB: 17 (31%), p = 1.0). In 107 (99%) patients, successful PVI was achieved. Transient phrenic palsy omitted complete PVI in one CB patient. A trend for a shorter overall procedure duration was observed in the PFA group (PFA: 64.5 ± 17.5 min; CB: 73.0 ± 24.8 min; p = 0.07). Excluding LA mapping time (first 14 cases), procedure time was significantly shorter using PFA (PFA: 58.0 ± 12.5 min, CB: 73.0 ± 24.8 min, p = 0.0001). Fluoroscopy time was significantly longer for PFA (PFA: 15.3 ± 4.7 min, CB: 12.3 ± 5.3 min; p = 0.001), but significantly less contrast medium was used (PFA: 12 ± 6 mL; CB: 51 ± 29 mL, p < 0.0001). Subgroup analysis of the PFA group revealed a significant shortening of procedure duration over time (first tertile: 72.7 ± 13.5 min, second tertile: 67.3 ± 21.7 min, third tertile: 53.4 ± 9.8 min, first vs. third tertile p < 0.0001). Two cardiac tamponades occurred in the PFA group (p = 0.495), of which one was most likely related to complex transseptal puncture. In the first 48 h after PVI, the number of prescribed analgesics due to postprocedural pain was equal between both groups (PFA: 7 (13%) patients, CB: 10 (19%) patients, p = 0.598). After a FU of 273 ± 129 days,35 of 47 patients (74%) after PFA and 36 of 50 patients (72%) after CB PVI were free of any atrial arrhythmia (HR: 0.98, p = 0.88). Only in the PFA group, a significant increase in HR 3 months after PVI was observed (pre-PVI: 61 ± 8 beats/min, post-PVI: 65 ± 9 beats/min, p = 0.008). The new PFA technology is equally effective and safe as compared to CB for complete PVI with potentially shorter procedure time and significantly less contrast medium. However, AF recurrence rates after PFA PVI seem to be comparable to CB PVI.

Background Catheter ablation for atrial fibrillation (AF) is increasing as rhythm control therapy. Besides thermal ablation approaches, such as cryoballoon ablation (CBA), a novel non-thermal and tissue-specific ablation modality – pulsed field ablation (PFA) – has been introduced. Left atrial reservoir strain (LArS) has been suggested to predict arrhythmia recurrences after AF ablation. Up to now, data describing LArS in patients undergoing their first AF ablation using PFA or CBA are sparse. Purpose To compare LArS in patients undergoing first catheter ablation for AF using either PFA or CBA. Methods Patients with transthoracic echocardiography prior to their first catheter ablation for AF were included. Patients in AF during transthoracic echocardiography, with poor 2D image quality and those that did not have a transthoracic echocardiography after AF ablation were excluded. Clinical characteristics and echocardiography parameters were analyzed. LArS was measured before and after AF ablation and was correlated with the recurrence of atrial arrhythmias in the follow-up period. Results Of 267 patients undergoing their first AF ablation, 67 patients (69% male, 65 ± 11 years) fulfilled the inclusion criteria and were further analyzed. AF ablation was performed using PFA in 55% and CBA in 45% of patients. Baseline characteristics were similar in both groups. Before ablation LArS was similar for PFA (17.69 ± 6.92%) and CBA patients (19.38 ± 9.42%, P=0.45). After AF ablation, LArS did not change significantly compared to the values before (before ablation: 20.96 ± 15.9 vs. after ablation: 19.87 ± 9.38, P=0.18), irrespective of the ablation mode (PFA before: 17.69 ± 6.92%vs. PFA after: 18.06 ± 8.9%, P=0.53; CBA before: 19.38 ± 9.42% vs. CBA after: 21.08 ± 9.48%, P=0.36). After a median of 190 days [95% confidence interval: 89 - 454 days], 25 patients (37%) experienced an arrhythmia recurrence (PFA: 38%, CBA: 37%). Comparing patients with and without arrhythmia recurrences, LArS before catheter ablation was lower in those experiencing an arrhythmia recurrence (16.02 ± 6.8%) compared to those without arrhythmia recurrence (25.58 ± 20.32%, P=0.02). However, this was independent from the ablation mode (PFA: AF-recurrence: 16.51 ± 4.27 vs. no recurrence: 21.31 ± 15.9, P=0.19; CBA: AF-recurrence: 15.48 ± 9.03 vs. no recurrence: 27.34 ± 22.14, P=0.07). Univariable regression analysis - including sex, age and comorbidities - revealed a trend for baseline LArS being associated with arrhythmia recurrence (HR 0.92, 95% CI: 0.86 – 1.01; P=0.065). Conclusions This hypothesis generating study indicates that LArS is not affected by AF ablation irrespective of the ablation mode. Patients with lower LArS before ablation had more arrhythmia recurrences independent of the ablation mode. A larger patient population is needed to assess the association of LArS and arrhythmia recurrences after AF ablation using different ablation modalities.

PO-04-042 GENDER DIFFERENCES IN CLINICAL OUTCOMES AFTER PULSED FIELD ABLATION OF ATRIAL FIBRILLATION: INTERIM ANALYSIS OF THE MANIFEST-PF EFFICACY REGISTRY

Cryoablation: Sooner or Later?

BackgroundPulmonary vein antrum isolation (PVAI) is the cornerstone of atrial fibrillation (AF) ablation, but the clinical outcomes of PVAI are unsatisfactory in patients with persistent AF and a large left atrium (LA).ObjectivesWe investigated the clinical outcomes following radiofrequency ablation (RFCA), cryoballoon ablation (CBA), and thoracoscopic maze in patients with persistent AF and a large LA.MethodsWe included patients with consecutive persistent AF who had a large LA (LA diameter >50 mm) and underwent RFCA, CBA, or thoracoscopic maze surgery. In the RFCA group, additional linear ablation was performed at the physician’s discretion. The endpoint was 12 months without recurrence of an atrial arrhythmia, including AF, atrial flutter, and atrial tachycardia, following a 90-day blanking period.ResultsWe recruited 89 persistent AF patients with a large LA who underwent RFCA (n = 32), CBA (n = 38), or the thoracoscopic maze procedure (n = 19). During the 12-month follow-up, 48 (53.9%) cases of AF recurrence were observed. There was no prognostic difference between groups (50.0% in RFCA vs. 52.6% in CBA vs. 63.2% in thoracoscopic maze, all P > 0.05). Early recurrence during the blanking period was a significant predictor of late recurrence for RFCA and CBA, but not for the thoracoscopic maze.ConclusionIn persistent AF patients with a large LA, we did not find a prognostic difference RFCA, CBA, or a thoracoscopic maze procedure in recurrence of atrial arrhythmia. Early recurrence predicted late recurrence in catheter ablation, but not in thoracoscopic maze.