Left Atrial Posterior Wall Ablation Research Articles

Outcomes of hybrid surgical ablation and concomitant left atrial appendage exclusion in long-standing persistent atrial fibrillation.

Management of patients with long-standing persistent atrial fibrillation (LSPAF) presents a clinical challenge. Hybrid convergent ablation has been shown to have superior efficacy compared to endocardial-only ablation. However, data on concomitant left atrial appendage (LAA) management along with hybrid ablation is sparse. We aimed to evaluate the effectiveness of concomitant hybrid convergent ablation and LAA clipping in patients with LSPAF. We conducted a retrospective analysis of all patients with LSPAF who underwent hybrid surgical ablation with LAA clipping at our institution. The primary endpoint was a recurrence of atrial arrhythmias at 12 months. Further, the durability of surgical left atrial posterior wall ablation was examined during the endocardial catheter ablation using standing electrophysiological criteria. A total of 79 patients were included. Mean age was 63.5 ± 9.6 years, and 71% were males. LAA clipping was performed in 99% of patients. The mean time between the surgical and endocardial stages of the procedure was 2.6 ± 1.7 months. Persistent posterior wall activity was observed in 34.2% (n = 27/79) patients during the endocardial phase of the procedure. Cardiac implantable electronic device was used in 74% of patients for monitoring of recurrence of atrial fibrillation (AF). The primary effectiveness of AF freedom at 12 months was 73.8% (45/61). Over a 12-month follow-up period, 11.4% (9/79) of patients required repeat catheter ablation, of which 88.9% (8/9) had evidence of persistent posterior wall activity. Concomitant hybrid convergent ablation and LAA exclusion with an atrial clip provides reasonable long-term AF-free survival in patients with LSPAF. Persistent posterior wall activity is seen commonly in patients presenting with recurrent AF following hybrid convergent AF ablation.

Safety and effectiveness of additional left atrial posterior wall ablation using pulsed field ablation for persistent and long-standing persistent atrial fibrillation patients.

The unique safety profile of pulsed field ablation (PFA) has made pulmonary vein isolation (PVI) + left atrial posterior wall (LAPW) ablation promising for treating persistent atrial fibrillation (PerAF). The goal of this study was to assess long-term freedom from atrial fibrillation, atrial flutter, and atrial tachycardia (AF/AFL/AT), as well as the safety and feasibility of LAPW PFA using multipolar, pentaspline Farawave catheter. Retrospective observational study at a single institution. Data for 94 patients were collected from a prespecified intraprocedural registry. The long-term AF/AFL/AT recurrence assessment was based on an analysis of medical history; 24-h Holter ECGs at 3, 6, and 12 months postablation; and 12-lead ECGs recorded during symptomatic episodes or visits. Half of the patients had ls-PerAF, and half had a history of catheter ablation-mostly RF PVI. The acute ablation success rate was 100%, and the primary safety outcome was observed in 2 patients. Fifty patients experienced AF/AFL/AT recurrence (54.3%). An increase in LAPW low-voltage areas and AF classification were associated with arrhythmia recurrence. After a median follow-up of 13 months, the Kaplan‒Meier estimated median time free of AF/AFL/AT after a single procedure was 14.7 months. PFA PVI + PWA had the best outcome in perAF patients without extensive LA fibrosis. AF recurrence was paroxysmal in significant part of the cohort. The addition of PWA to PVI using multipolar PFA was safe and did not significantly influence the transpired ablation time.

Procedural safety and outcome of additional left atrial posterior wall ablation using pulse field ablation for atrial fibrillation

Abstract Introduction Pulsed field ablation (PFA) has recently been shown to be comparable to radiofrequency ablation and cryoablation in terms of acute safety and outcome for pulmonary vein isolation (PVI) for atrial fibrillation (AF). Efficacy and safety of additional left atrial posterior wall ablation (LAPWA) is unknown. We hereby report safety profile and short-term success at 6 months. Methods Consecutive patients with paroxysmal or persistent atrial fibrillation who underwent PFA were included. Procedures were performed under conscious sedation or general anaesthesia, with or without intracardiac echocardiography/ pre- or post-ablation electroanatomic mapping at the operators’ discretion. Safety endpoints included all-cause death within 30 days, cardiac tamponade, stroke/ TIA, MI, diaphragmatic paralysis, AE fistula. Primary efficacy endpoint was arrhythmia recurrence after 90 days blanking period at 6 months. LAPWA was performed using 2.0 kV biphasic waveforms, 2 deliveries for each application site. The lesion set depended on the patient’s AF ablation history, LA size, and anatomy. After LA mapping post PVI (index or re-do), 2 anchor lesions per vein extending to the LAPW were deployed. A lesion set was then performed between the anchor lesions on the LAPW (upper and lower row) with the catheter in a flower configuration and the intention of 50% overlap for the neighbouring application sites at 3D EAM. Results Seventy-two (76% males) patients underwent PFA for AF, 55 (76.4%) were paroxysmal and 4 (5.6%) were redo cases. 19 (72%) underwent additional LAPWA. LAPWA was more likely performed in patients with persistent AF (57.9% vs 11.3%, p<0.001), require GA (p=0.043), with 100% EAM use (p=0.026). While total PFA applications was expectedly higher in the LAPWA group (65.7 ± 12.4 vs 42.9 ± 9.0, p<0.001), there were no significant differences in PFA dwell time in LA (44.2 ± 14.8 vs 42.3 ± 15.5min, p=0.628), procedural time (121.3 ± 43.8 vs 119.2 ± 49.4min, p=0.866) and fluoroscopic dose, AK (130 ± 107 vs 139 ± 102mGy, p=0.748). Average number of applications required for LAPW was 18 applications. LAPW isolation was acutely successful in all 19 patients on EAM. There were 6 inpatient complications of which all happened in the non-LAPWA group and unrelated to PFA. Arrhythmia recurrence was comparable at 6 months (11.1% vs 8.9%, p=1.00). Conclusion Additional LAPWA on top of PVI using PFA is safe with excellent acute isolation of posterior wall and does not increase procedural nor fluoroscopic duration. Short term outcome appears comparable and LAPWA may be useful especially in patients with persistent AF who may not be able to tolerate long procedures but will benefit from durable rhythm control.

Impact of Left Atrial Posterior Wall Ablation During Pulsed-Field Ablation for Persistent Atrial Fibrillation

BackgroundPulmonary vein isolation (PVI) alone is insufficient to treat many patients with persistent atrial fibrillation (PersAF). Adjunctive left atrial posterior wall (LAPW) ablation with thermal technologies has revealed lack of efficacy, perhaps limited by the difficulty in achieving lesion durability amid concerns of esophageal injury. ObjectivesThis study aims to compare the safety and effectiveness of PVI + LAPW ablation vs PVI in patients with PersAF using pulsed-field ablation (PFA). MethodsIn a retrospective analysis of the MANIFEST-PF (Multi-National Survey on the Methods, Efficacy, and Safety on the Post-approval Clinical Use of Pulsed Field Ablation) registry, we studied consecutive PersAF patients undergoing post-approval treatment with a pentaspline PFA catheter. The primary effectiveness outcome was freedom from any atrial arrhythmia of ≥30 seconds. Safety outcomes included the composite of acute and chronic major adverse events. ResultsOf the 547 patients with PersAF who underwent PFA, 131 (24%) received adjunctive LAPW ablation. Compared to PVI-alone, patients receiving adjunctive LAPW ablation were younger (65 vs 67 years of age, P = 0.08), had a lower CHA2DS2-VASc score (2.3 ± 1.6 vs 2.6 ± 1.6, P = 0.08), and were more likely to receive electroanatomical mapping (48.1% vs 39.0%, P = 0.07) and intracardiac echocardiography imaging (46.1% vs 17.1%, P < 0.001). The 1-year Kaplan-Meier estimate for freedom from atrial arrhythmias was not statistically different between groups in the full (PVI + LAPW: 66.4%; 95% CI: 57.6%-74.4% vs PVI: 73.1%; 95% CI: 68.5%-77.2%; P = 0.68) and propensity-matched cohorts (PVI + LAPW: 71.7% vs PVI: 68.5%; P = 0.34). There was also no significant difference in major adverse events between the groups (2.2% vs 1.4%, respectively, P = 0.51). ConclusionsIn patients with PersAF undergoing PFA, as compared to PVI-alone, adjunctive LAPW ablation did not improve freedom from atrial arrhythmia at 12 months.

Left atrial posterior wall isolation using pulsed-field ablation: procedural characteristics, safety, myocardial injury and short-term outcomes

Abstract Background Pulsed-field ablation (PFA) has emerged as a novel treatment strategy for patients with atrial fibrillation (AF). Among targets beyond pulmonary vein isolation (PVI), ablation of the left atrial posterior wall (LAPW) has gained increased interest in patients with persistent AF. PFA offers a novel ablation technology possibly able to overcome the obstacles of incomplete isolation and concerns of damage to adjacent structures. Purpose To assess procedural characteristics, safety, myocardial injury and short-term outcomes of patients undergoing LAPW ablation in a clinical setting. Methods Consecutive patients undergoing PFA PVI with LAPW isolation were included. Using a multi-spline PFA catheter in a flower configuration, two anchor lesions per vein extending to the LAPW were deployed. Then, the wire was pulled back into the lumen, the PFA catheter and sheath were rotated along the entire LAPW in a flower configuration thereby creating overlapping lesions as assessed by a 3D-electro-anatomical mapping system. First-pass isolation was controlled using a multipolar mapping catheter. Complications were checked with an echocardiogram, high sensitivity cardiac troponin T was measured the next day and for recurrence detection a Holter ECG was performed during follow up. Results 25 patients with persistent AF undergoing PVI were included (age 69 ± 12 years, left atrial volume index 37 ml/m2). 17 patients underwent redo-PVI with LAPW and 8 patients first time PVI with LAPW ablation. The median number of applications to perform LAPW isolation using PFA was 24 (IQR 14-28). The median procedure time was 69 min (IQR 56-81). The median LA dwell time was 59 min (IQR 49-72). The median fluoroscopy time was 10 min (IQR 8-14). First-pass isolation was achieved in 24/25 cases (95%). There were no complications. High sensitivity cardiac troponin T level post-procedurally was 951 ng/L (IQR 717-1189). Median duration of follow-up were 95 days, (IQR 84-184), AF recurrence was observed in 2 patients (8%). Conclusion LAPW ablation with PFA appears safe and results in high acute isolation rates. The optimal technique to perform LAPW ablation using PFA needs to be defined. Data on long-term outcomes are missing.

Catheter ablation using pulmonary vein isolation with versus without left atrial posterior wall isolation for persistent atrial fibrillation: an updated systematic review and meta-analysis.

Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation of atrial fibrillation (AF); however, the results are suboptimal for persistent AF. The left atrial posterior wall (LAPW) is thought to be a major additional area in initiation and perpetuation of persistent AF. Therefore, adjunctive ablation of the posterior wall may reduce AF recurrence in patients with persistent AF. The objective of this study was to compare outcomes of catheter ablation in patients with persistent AF using PVI alone versus a combination of PVI and LAPW isolation. Literature search was conducted in PubMed, PubMed Central, Scopus, and Embase since inception to February 2023. Screening of studies was done via Covidence software. Risk of bias assessment was done using appropriate tools. Data extraction and a narrative synthesis were carried out accordingly. Ten studies were included, of which five were randomized controlled trials. PVI with LAPW ablation group had significantly lower recurrence of overall atrial tachyarrhythmia (OR 0.47, CI 0.32-0.70) and AF (OR 0.39, CI 0.23-0.69). In sensitivity analysis, freedom from atrial arrhythmias was noted to be significantly higher in the PVI with LAPW ablation group (OR 2.22, CI 1.36-3.64). However, there was no significant difference in occurrence of atrial flutter (OR 1.36, CI 0.86-2.14) or with periprocedural adverse events (OR 1.10, CI 0.60-1.99). LAPW ablation, in addition to PVI, significantly improves the rates of arrhythmia freedom and reduces the recurrence of overall atrial tachyarrhythmia. There was no significant difference in atrial flutter or periprocedural adverse events.

Pulsed-field ablation of pulmonary vein and left atrial posterior wall combined with left atrial appendage occlusion as single procedure.

Pulmonary vein isolation and left atrial posterior wall ablation using the Farapulse system, followed by left atrial appendage occlusion, have been achieved as single combined procedure to treat long-standing persistent atrial fibrillation in a patient at high hemorrhagic risk.

PO-01-104 3D MODELING OF PRE-PROCEDURE CT SCAN TO PREDICT SEVERE ESOPHAGEAL HEATING DURING HIGH POWER SHORT DURATION ATRIAL FIBRILLATION ABLATION

The degree of esophageal heating during left atrial posterior wall (LAPW) ablation is a powerful predictor of esophageal injury. Esophageal temperature monitoring has not been shown, however, to reduce esophageal injury risk related to atrial fibrillation (AF) ablation. Esophageal proximity modeling based on pre-procedure CT scan using ADAS 3D software (ADAS3D Medical, Barcelona, Spain) is a novel method of identifying left atrial locations at high risk for severe esophageal heating. Given the mobile nature of the esophagus relative to the LAPW, the predictive value of esophageal proximity mapping is unclear. To determine the predictive value of esophageal proximity mapping to identify LAPW ablation sites at risk for severe esophageal heating. Pre-procedure CT scans were analyzed using ADAS 3D software in 10 patients undergoing AF ablation to create a 3D esophageal proximity model and left atrial tissue thickness map that were merged with a catheter based left atrial electroanatomic map (Ensite X, Abbott, Inc.). Esophageal proximity was defined as: Zone 1 – overlying esophagus, Zone 2 – within 5 mm of esophagus, or Zone 3 – > 5 mm from esophagus. LAPW ablation lesions were created with a contact-force sensing radiofrequency ablation catheter (Tacticath, Abbott, Inc.) at 45W, 10-20g of force, and 6 seconds duration. A 12 sensor esophageal temperature probe (Circa, Circa Scientific, Inc.) recorded the temperature increase related to each LAPW lesion. Ablation lesions in Zone 3 resulted in significantly lower esophageal temperature rise (degrees Celsius) as compared to either Zone 1 (mean 0.11 ± 0.27 vs 1.61 ± 1.39, p value <0.0001) or Zone 2 (mean 0.11 ± 0.27 vs 0.84 ± 1.1, p value <0.0001) (Fig A). Lesions in Zone 2 resulted in lower temperature rise as compared to Zone 1 (mean 0.84 ±1.1 vs. 1.61 ± 1.39, p value <0.0001) (Fig A). Within Zones 1 and 2, lesions with LAPW thickness > 2 mm resulted in significantly less esophageal temperature rise as compared to those on tissue with thickness of ≤ 2 mm (Fig B). Ablation lesions delivered >5mm from esophageal location at time of pre-procedure CT scan are very unlikely to result in significant esophageal heating. Ablation sites overlying esophagus with LAPW thickness ≤ 2mm were at greatest risk of significant esophageal heating. Analysis of pre-procedure CT scans to determine esophageal proximity and LAPW thickness may be useful in developing strategies to avoid esophageal injury during LAPW RF ablation.

AB-452663-4 LEFT ATRIAL POSTERIOR WALL ABLATION USING PULSED FIELD ABLATION AS ADJUNCTIVE THERAPY DURING RE-DO PROCEDURES AFTER MULTIPLE FAILED PULMONARY VEIN ISOLATIONS USING THERMAL ENERGY

Pulmonary vein isolation (PVI) is the cornerstone for patients with atrial fibrillation (AF). Long-term efficacy is limited because of high PV reconnection rates. Ablation targets and strategies beyond PVI in re-do left atrial (LA) procedures have failed to improve outcome. Pulsed field ablation (PFA) has recently been introduced as a novel ablation technology. We report the first experience of re-do PVI with adjunctive LA posterior wall ablation (LAPWA) in patients with multiple failed LA procedures using thermal energy (RF /cryo). After high-density bipolar 3D voltage maps using a pentaspline diagnostic catheter, ablation was performed in conscious sedation using a steerable sheath and a pentaspline over-the-wire basket and flower PFA catheter. After re-do PVI (irrespective of PV status), the pentaspline catheter was visualized in the 3D mapping system. The posterior wall was ablated using the PFA catheter in the flower configuration (Figure). Projected catheter images overlapped approx. 30% between sites across the posterior wall. Per ablation site, 4 applications were administered. Post ablation, 3D voltage maps confirmed complete PVI and LAPWA. Bidirectional PVI was also documented using pacing. Procedural parameters, acute success, in-hospital safety and arrhythmia recurrence were assessed. Between Sept. 2021 and Nov. 2022, 17 patients were enrolled. Mean age was 68±8 years. Time since first AF diagnosis was 72±46 months. Mean number of previous LA procedures was 3±1. Acute PVI and LAPWA were 100% successful. Median procedural time was 160±62 min (including 47±10 min for pre and post mapping). LA dwell time of the PFA catheter was 46±19 min. Fluoroscopy time and dose area product were 24±09 min and 13±13 Gy.cm2. All patients tolerated this approach without procedural interruption. There were no acute or chronic complications. After a follow-up of 163±105 days, 12/17 (71%) patients were free of documented AF, atrial flutter or tachycardia. In patients with multiple failed LA ablations for AF, re-do PVI (irrespective of PV status) and LAPWA using PFA seems to be a safe and feasible approach with promising short-term results. Larger studies are needed to investigate long-term efficacy and safety in this patient group with otherwise very limited therapeutic options.

Coronary Arterial Spasm During Pulsed Field Ablation to Treat Atrial Fibrillation.

Pulsed field ablation (PFA) has a unique safety profile when used to treat atrial fibrillation, largely related to its preferentiality for myocardial tissue ablation, in particular, esophageal sparing. A pentaspline catheter was the first such PFA system studied clinically for atrial fibrillation ablation; in these initial regulatory trials, the catheter was used for pulmonary vein isolation and left atrial posterior wall ablation. Since its regulatory approval in Europe, in clinical practice, physicians have ablated beyond pulmonary vein isolation and left atrial posterior wall ablation to expanded lesion sets in closer proximity to coronary arteries. This is an unstudied important issue because preclinical and clinical data have raised the potential for coronary arterial spasm. Herein, we studied the vasospastic potential of PFA lesion sets, both remote from and adjacent to coronary arteries. During routine atrial fibrillation ablation using the pentaspline PFA catheter, coronary angiography was performed before, during, and after pulsed field applications. The lesion sets studied included: (1) those remote from the coronary arteries such as pulmonary vein isolation (n=25 patients) and left atrial posterior wall ablation (n=5), and (2) ablation of the cavotricuspid isthmus (n=20) that is situated adjacent to the right coronary artery. During pulmonary vein isolation and left atrial posterior wall ablation, coronary spasm did not occur, but cavotricuspid isthmus ablation provoked severe subtotal vasospasm in 5 of 5 (100%) consecutive patients, and this was relieved by intracoronary nitroglycerin in 5.5±3.5 minutes. ST-segment elevation was not observed. However, no patient (0%, P=0.004) had severe spasm if first administered parenteral nitroglycerin, either intracoronary (n=5) or intravenous (n=10), before treatment. Coronary vasospasm was not provoked during PFA at locations remote from coronary arteries, but when the energy is delivered adjacent to a coronary artery, PFA routinely provokes subclinical vasospasm. This phenomenon is attenuated by nitroglycerin, administered either post hoc to treat spasm or as prophylaxis.

Left atrial posterior wall isolation—The conundrum of safety versus efficacy

The study by Worck et al. raises interesting findings with regard to left atrial posterior wall ablation. The utility of ablation at the CRZ - which may represent epicardial connection via the septopulmonary bundle - warrants future research. Upcoming trials utilising existing technology, along with increased availability of pulsed field ablation, will advance our knowledge of the impact of left atrial posterior wall isolation. This article is protected by copyright. All rights reserved.

Additional left atrial posterior wall ablation using pulsed field ablation as a safe and feasible treatment option for persistent atrial fibrillation patients

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): University Hospital Center Split Background Catheter ablation in persistent (PeAF), and especially long-standing persistent AF (ls-PeAF) patients often requires ablation beyond pulmonary vein isolation (PVI) (1). Adjunctive ablation of the left atrial posterior wall (LAPW) may improve outcomes of PeAF patients but has been limited by the difficulty of achieving lesion durability and concerns of thermal damage of nearby structures. Pulsed field ablation (PFA) is a new, nonthermal ablative modality, with proven myocardial ablative efficacy, quick energy delivery, and a favorable safety profile, which makes PFA suitable for the LAPW ablation (2). Purpose We aimed to report the safety profile, intraprocedural parameters, and acute success rate of LAPW ablation in a regular clinical setting with the CE-marked PFA platform. Methods This was a prospective observational study on the safety and feasibility aspects of LAPW ablation with the PFA in PeAF and ls-PeAF patients. The safety endpoints included the percentage of clinically relevant complications, including stroke/TIA, atrioesophageal fistula, cardiac tamponade, myocardial infarction, diaphragmatic paralysis, and death in the first 30-days post-procedure. Acute ablation success was confirmed with electroanatomical mapping (EAM). Ablation was performed using 2.0 kV biphasic waveforms, 2 deliveries for each application site. The lesion set depended on the patient’s AF ablation history, LA size, and anatomy. After LA mapping and PVI or PVI touch-up (index or re-do procedure), 2 anchor lesions per vein extending to the LAPW were deployed. A lesion set was then performed between the anchor lesions on the LAPW (upper and lower row) with the catheter in a flower configuration and the intention of 75% overlap for the neighbouring application sites at 3D EAM. Results Twenty-three patients (87% men) received PFA LAPW ablation. The age median was 64 (Q1-Q3: 56.5-71) years. 52% had ls-PeAF and 65% had previous ablation. The median LA diameter was 47 mm (Q1-Q3: 46-52 mm). The safety endpoints did not occur in any of the patients. The LA ablation catheter dwell time median for the index and re-do procedure was 39.5 (Q1-Q3: 31-42.25) and 18 (Q1-Q3: 16-21) minutes. The median time for LAPW ablation was 10 (Q1-Q3: 8-12) minutes. The median number of application sites on the upper and lower posterior wall was 6 (Q1-Q3: 5-7) and 6 (Q1-Q3: 5-7), respectively. Acute ablation success was 100% in terms of completed box lesion, and LAPW electrical activity loss. In a single case, first-pass ablation was not achieved, but additional delivery under intracardiac echocardiography guidance resulted in the electrical silence of the targeted segment. Conclusion LAPW ablation with PFA is safe, quick and results in excellent acute isolation rates in PeAF patients. Posterior wall ablation with PFA is not a time-consuming procedure which is an important aspect for real-world PeAF and ls-PeAF patients who are often fragile.

Pulsed field ablation as the first choice regarding oesophageal safety for atrial fibrillation ablation?

Abstract Funding Acknowledgements Type of funding sources: None. Background The occurrence of endoscopy-detected oesophageal lesions has been reported in patients with atrial fibrillation (AF) after thermal-based pulmonary vein isolation (PVI) with even higher risk in patients undergoing ablation of the left atrial posterior wall (LAPW) (1). The main mechanism of oesophageal injury is thermal, resulting in oesophageal dysmotility, ulceration, perforation, or left atrio-oesophageal fistula formation, which are rare but life-threatening sequelae. Pulsed-field ablation (PFA) is a non-thermal ablation technology that uses high amplitude pulsed electrical fields to ablate tissues through cell membrane disruption (2). Precommercial experience with PFA reported no injury to the oesophagus for both PVI and LAPW ablation (3). Purpose To assess oesophageal safety in AF patients treated with three different PFA platforms. Methods In this single-centre experience we retrospectively analysed a total of 72 upper gastrointestinal (GI) endoscopies performed by a certified gastroenterologist one day after left atrial PFA. GI analysis focused on detection of oesophageal lesions nearest the left atrium and evidence of gastric hypomotility. PVI was performed using focal or single shot PFA catheters. Focal PFA catheters achieved PVI using the wide antral circumferential ablation (WACA) technique. LAPW ablation was performed exclusively by using single shot PFA devices. Results The patient characteristics were summarized in Table 1. Focal PFA catheters were used in 78% of patients. Post-procedure endoscopies revealed no mucosal lesions in any patient. Gastroparesis and perioesophageal vagal nerve injury were not found (Table 2). Conclusion PFA, whether applied by single shot devices or focal catheters, seems to be a safe ablation option with respect to oesophageal injury resulting from PVI and LAPW ablation in paroxysmal and persistent AF patients. Irrespective of catheter design, PFA configuration (monopolar versus bipolar, maximum output), or LA lesion set, we found absolute GI safety of PFA as class effect.

Abstract 10208: Quantitative Comparison of Ablation Area Created by the Conventional- and Larger-Sized Visually Guided Laser Balloon

Introduction: The visually guided laser balloon (VGLB) ablation catheter has been designed to facilitate pulmonary vein (PV) isolation in patients with atrial fibrillation (AF). Because VGLB is characterized by a compliant and variable diameter balloon, the balloon at the larger inflation size can isolate wider-area circumferential PV antrum. Though the importance of a wider circumferential isolation of PVs, which includes a large portion of the left atrial posterior wall (LAPW), has been suggested in several studies, the extension of the isolation area created by the new VGLB technique remains to be elucidated. We report the quantitative examination of the isolation areas after the conventional- and larger-sized VGLB ablation. Methods: Fifty-five patients with AF who underwent VGLB ablation were enrolled in this prospective study. An electroanatomic map of the left atrium was obtained with the PENTARAY catheter and the CARTO-3 system before and after PV isolation using conventional-sized VGLB. The isolation areas were extended by the larger-sized VGLB ablation and remapped in the same way. As demonstrated in figure, the isolation areas were measured after each ablation. Results: After PV isolation using the conventional-sized VGLB, the mean left- and right-sided antral PV surface areas of ablation were 13.5±2.9 cm 2 and 16.4±3.7 cm 2 , respectively. The total area of LAPW ablation was 10.9±2.1 cm 2 (45.6±9.3% of the posterior wall). On the other hand, they were 18.6±4.0 cm 2 , 23.7±5.2 cm 2 and 16.3±2.8 cm 2 (65.9±11.2%) after ablation with the larger-sized VGLB. These results revealed that the new VGLB technique yielded statistically greater areas of isolation than the conventional-sized VGLB. Conclusions: The larger VGLB ablation technique can create a significantly wider antral PV and LAPW isolation than the conventional-sized VGLB. The resulting LAPW debulking may be greater than the other balloon-based ablation lesions that have been reported previously.

Cryoballoon ablation of the left atrial posterior wall reduces recurrence of persistent atrial fibrillation in patients with non-paroxysmal atrial fibrillation.

BackgroundThis study aimed to clarify the clinical outcomes of cryoballoon ablation of the left atrial (LA) posterior wall (LAPW), including the LA roof, in patients with non‐paroxysmal atrial fibrillation (AF).MethodsWe analyzed the outcomes of 284 patients with non‐paroxysmal AF, of whom 210 underwent the cryoballoon ablation of the LAPW, including the LA roof, in addition to pulmonary vein isolation with a cryoballoon.ResultsComplete conduction block at the LA roof was obtained in 95.7% (201/210) of patients, and LAPW was isolated in 83.3% (130/156) of patients. Over 372 (range, 208–477) days of follow‐up, atrial arrhythmia recurrence was observed in 84 (29.6%) patients, and atrial tachycardia (AT) recurrence accounted for 27.4% of cases. The prevalence of LA roof cryoballoon ablation was significantly higher in patients without recurrence than in those with recurrence (78.6% vs. 63.1%, respectively; p = .01), especially those with persistent AF recurrence (77.0% vs. 55.0%, p = .01). No significant difference was found in the prevalence of AT recurrence between patients who had undergone additional LAPW ablation and those who had not. Durable LA roof lesions were confirmed in 29 (72.5%) of 40 patients who underwent redo ablation.ConclusionsCryoballoon ablation of the LAPW leads to a sufficient acute success rate of complete conduction block and durable lesions of the LA roof without increasing AT recurrence risk. The prevalence of persistent AF recurrence decreases after additional cryoballoon ablation of the LAPW in patients with non‐paroxysmal AF.

B-PO03-100 CARDIAC ENZYME ELEVATION AND SHORT TERM CLINICAL OUTCOME AFTER CRYOBALLOON ABLATION OF LEFT ATRIAL POSTERIOR WALL FOR PERSISTENT ATRIAL FIBRILLATION

The effectiveness of left atrial posterior wall (LAPW) ablation using cryoballoon (CB) ablation was not sufficiently evaluated. We aim to compare the degree of myocardial injury and early clinical outcome of LAPW or roof line using CB ablation to those using RFCA (radiofrequency catheter ablation). A total of 100 patients with persistent atrial fibrillation (AF) (66.7% long standing persistent AF, 49 CB and 51 RFCA) were enrolled from 2017 to 2020. Patients underwent pulmonary vein isolation (PVI) with LAPW using CB or RFCA. Acute successful ablation of LAPW was defined as complete elimination of local electrical activities in LAPW. The completeness of roof line was assessed by bidirectional conduction block by differential pacing. The main outcomes were level of cardiac enzyme (troponin-I) elevation after procedure and early recurrence of atrial fibrillation or flutter. Acute successful ablation of LAPW or roof line was achieved in 64.5% of RFCA group and 69.4% of CB group (P=0.698). Total procedure time (CB 145.6 ± 54.5 min vs. RF 184.0 ± 62.1 min, P=0.003) and ablation time (CB 2324.5 ± 660.2 min vs. RF 2855.3 ± 1101.3 min, P=0.005) was shorter in CB group. Troponin-I at one day after the procedure was more elevated in CB group compared with RFCA group (CB 11.6 ± 6.8 ng/mL vs. RFCA 5.0 ± 3.8 ng/mL, p<0.001). Rate of freedom from atrial tachyarrhythmia (AF for atrial flutter) at 3months were comparable between 2 groups (CB 59.2% vs. RFCA 66.7%, P=0.57). In patients with persistent AF who underwent PVI and LAPW ablation or roof line ablation, cardiac enzyme elevation is more prominent and short term clinical outcome is comparable in CB ablation group compared with RFCA group.

Long-term follow-up of thoracoscopic ablation for long-standing persistent atrial fibrillation

Abstract Background Catheter ablation in patients with long-standing persistent AF (LSPAF) remains challenging and often requires repeated procedures with variable results. We report long-term outcomes of a bipolar thoracoscopic pulmonary vein and left atrial posterior wall ablation for LSPAF, and compare continuous and interval rhythm monitoring. Methods Seventy-seven LSPAF patients who underwent thoracoscopic pulmonary vein and box isolation between 2009–2017 in two Dutch centers were included. Follow-up consisted of continuous rhythm monitoring using an implanted loop recorder or 24-h Holter at 3/6/12/24/60 months. Results Mean age was 59±8 years with a median AF duration of 3.8 [1.2–6.3] years. In the total cohort, at 2-year follow-up, 86.0% of patients were in sinus rhythm, 12.3% were in paroxysmal AF and 1.6% in persistent AF. At 5 years, 62.9% of patients were in sinus rhythm, 20.0% in paroxysmal AF, 14.3% in persistent AF and 2.9% was experiencing atrial flutter. Continuous rhythm monitoring was performed in 46% of patients. Comparing continuous and interval rhythm monitoring, freedom from any atrial arrhythmia episode at 2- and 5 years was 60.0% and 49.9% in the continuous group and 93.8% and 51.9% in the interval monitoring group, respectively (p=0.02, Breslow-Wilcoxon test). In patients with continuous rhythm monitoring the mean atrial arrhythmia burden was reduced from 99.1% preoperatively to 0.1% at the end of the blanking period and 7.3% at 2-year follow-up. Conclusions Thoracoscopic box ablation is highly effective in restoring sinus rhythm at medium term follow-up. However, it is not a curative treatment as demonstrated by the 50% arrhythmia-free survival at long-term follow-up. Whether this is due to the progressive nature of AF needs further investigation. Continuous rhythm monitoring shows earlier recurrence detection with a potential early treatment adaptation. Funding Acknowledgement Type of funding source: None

Pulsed Field Ablation in Patients With Persistent Atrial Fibrillation

BackgroundUnlike for paroxysmal atrial fibrillation (AF), pulmonary vein isolation (PVI) alone is considered insufficient for many patients with persistent AF. Adjunctive ablation of the left atrial posterior wall (LAPW) may improve outcomes, but is limited by both the difficulty of achieving lesion durability and concerns of damage to the esophagus—situated behind the LAPW. ObjectivesThis study sought to assess the safety and lesion durability of pulsed field ablation (PFA) for both PVI and LAPW ablation in persistent AF. MethodsPersAFOne is a single-arm study evaluating biphasic, bipolar PFA using a multispline catheter for PVI and LAPW ablation under intracardiac echocardiographic guidance. A focal PFA catheter was used for cavotricuspid isthmus ablation. No esophageal protection strategy was used. Invasive remapping was mandated at 2 to 3 months to assess lesion durability. ResultsIn 25 patients, acute PVI (96 of 96 pulmonary veins [PVs]; mean ablation time: 22 min; interquartile range [IQR]: 15 to 29 min) and LAPW ablation (24 of 24 patients; median ablation time: 10 min; IQR: 6 to 13 min) were 100% acutely successful with the multispline PFA catheter alone. Using the focal PFA catheter, acute cavotricuspid isthmus block was achieved in 13 of 13 patients (median: 9 min; IQR: 6 to 12 min). The median total procedure time was 125 min (IQR: 108 to 166 min) (including a median of 28 min [IQR: 25 to 33 min] for voltage mapping), with a median of 16 min (IQR: 12 to 23 min) fluoroscopy. Post-procedure esophagogastroduodenoscopy and repeat cardiac computed tomography revealed no mucosal lesions or PV narrowing, respectively. Invasive remapping demonstrated durable isolation (defined by entrance block) in 82 of 85 PVs (96%) and 21 of 21 LAPWs (100%) treated with the pentaspline catheter. In 3 patients, there was localized scar regression of the LAPW ablation, albeit without conduction breakthrough. ConclusionsThe unique safety profile of PFA potentiated efficient, safe, and durable PVI and LAPW ablation. This extends the potential role of PFA beyond paroxysmal to persistent forms of AF. (Pulsed Fields for Persistent Atrial Fibrillation [PersAFOne]; NCT04170621)

Esophageal temperature dynamics during high-power short-duration posterior wall ablation

Increased peak luminal esophageal temperature (LET) is associated with increased risk of esophageal injury after left atrial posterior wall (LAPW) ablation. The magnitude, distribution, and risk factors of LET increase with high-power short-duration (HPSD) LAPW ablation are not well understood. The purpose of this study was to describe the spatial and temporal characteristics of LET changes associated with HPSD LAPW radiofrequency (RF) ablation. LET was sampled at 20 Hz using a 12-point esophageal temperature monitor (CIRCA S-CATH; Circa Scientific, Inc) in 16 patients undergoing LAPW ablation. Esophageal temperature sensor position and lesion locations were recorded using an electroanatomic mapping system with fluoroscopic integration (CARTO 3, CARTOUNIVU; Biosense Webster, Inc). Point-by-point LAPW ablation was performed at 50 W for 6 seconds. The first 20 LAPW lesions were individually analyzed in each patient. LET increase ≥4°C (8 lesions: max LET 5.8°C), 2°-4°C (34 lesions), and 1°-2°C (58 lesions) occurred at 9 ± 2 mm, 8 ± 2 mm, and 13 ± 2 mm from sensors, respectively. Lesions placed >20 mm from a temperature sensor did not result in an LET increase ≥2°C. Temperature resolution to within 1°C of baseline occurred ∼60 seconds after cessation of RF application. Consecutive lesions resulting in additive heating of at least 1°C occurred in 17 lesion pairs with an interlesion distance of 9 ± 4 mm and interlesion time of 21 ± 4 seconds. HPSD LAPW ablation can result in severe esophageal temperature increases. Significant LET increase will be undetected when lesions are >20 mm away from a temperature sensor. Additive LET increase was observed with consecutive lesions placed <20 mm apart within 60 seconds.

90Investigating the tissue response to radiofrequency ablation during left atrial posterior wall ablation: analysis of unipolar electrogram morphological changes following visitag-guided pulmonary vein isolation

90Investigating the tissue response to radiofrequency ablation during left atrial posterior wall ablation: analysis of unipolar electrogram morphological changes following visitag-guided pulmonary vein isolation