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Background: Rapid technologic development and expansion of procedural expertise have led to widespread proliferation of catheter-based electrophysiology procedures. It is unclear whether these advances come at cost to patient safety., Objective: This meta-analysis aimed to assess complication rates after modern electrophysiology procedures during the lifetime of the procedures., Methods: A comprehensive search was performed to identify relevant data published before May 30, 2023. Studies were included if they met the following inclusion criteria: prospective trials or registries, including comprehensive complications data; and patients undergoing atrial fibrillation ablation, ventricular tachyarrhythmia ablation, leadless cardiac pacemaker implantation, and percutaneous left atrial appendage occlusion. Pooled incidences of procedure-related complications were individually assessed by random effects models to account for heterogeneity. Temporal trends in complications were investigated by clustering trials by publication year (2000-2018 vs 2019-2023)., Results: A total of 174 studies (43,914 patients) met criteria for analysis: 126 studies of atrial fibrillation ablation (n = 24,057), 25 studies of ventricular tachyarrhythmia ablation (n = 1781), 21 studies of leadless cardiac pacemaker (n = 8896), and 18 studies of left atrial appendage occlusion (n = 9180). The pooled incidences of serious procedure-related complications (3.49% [2000-2018] vs 3.05% [2019-2023]; P < .001), procedure-related stroke (0.46% vs 0.28%; P = .002), pericardial effusion requiring intervention (1.02% vs 0.83%; P = .037), and procedure-related death (0.15% vs 0.06%; P = .003) significantly decreased over time. However, there was no significant difference in the incidence of vascular complications over time (1.86% vs 1.88%; P = .888)., Conclusion: Despite an increase in cardiac electrophysiology procedures, procedural safety has improved over time., Competing Interests: Disclosures Dr Reddy reports no disclosures related to this manuscript; but unrelated to this manuscript, he serves as a consultant for and has equity in Ablacon, Acutus Medical, Affera-Medtronic, Apama Medical–Boston Scientific, Anumana, APN Health, Aquaheart, Atacor, Autonomix, Axon Therapies, Backbeat, BioSig, CardiaCare, CardioNXT/AFTx, Circa Scientific, CoRISMA, Corvia Medical, Dinova-Hangzhou DiNovA EP Technology, East End Medical, EPD-Philips, EP Frontiers, Epix Therapeutics–Medtronic, EpiEP, Eximo, Farapulse–Boston Scientific, Field Medical, Focused Therapeutics, HRT, Intershunt, Javelin, Kardium, Keystone Heart, Laminar Medical, LuxMed, Medlumics, Middlepeak, Neutrace, Nuvera–Biosense Webster, Oracle Health, Restore Medical, Sirona Medical, SoundCath, Valcare; unrelated to this work, has served as a consultant for Abbott, Adagio Medical, AtriAN, Biosense-Webster, BioTel Heart, Biotronik, Boston Scientific, Cairdac, Cardiofocus, Cardionomic, CoreMap, Fire1, Gore & Associates, Impulse Dynamics, Medtronic, Novartis, Philips, Pulse Biosciences; and has equity in DRS Vascular, Manual Surgical Sciences, Newpace, Nyra Medical, Surecor, and Vizaramed. Dr Koruth has received grant support and stock options from Affera-Medtronic; unrelated to this manuscript, he has also served as a consultant to and has received grant support from Cardiofocus; has served as a consultant for Abbott, Boston Scientific, Biosense Webster, and Medtronic; and has received grant support from Pulse Bioscience. All other authors report no conflicts., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: During pulsed field ablation (PFA), electrode-tissue proximity optimizes lesion quality. A novel "single-shot" map-and-ablate spherical multielectrode PFA array catheter that is able to verify electrode-tissue contact was recently studied in a first-in-human trial of atrial fibrillation (AF)., Objective: The aim of this study was to report lesion durability data, safety, and 12-month effectiveness outcomes., Methods: The spherical PFA catheter, an all-in-one mapping and ablation system, was used to render anatomy and to deliver biphasic pulses (ungated 1.7 kV pulses; ∼40 seconds/application). Ablation sites included pulmonary veins (PVs) and, in selected patients, posterior wall and mitral isthmus. Follow-up was invasive remapping at ∼3 months, electrocardiograms, Holter monitoring at 6 and 12 months, and symptomatic and scheduled transtelephonic monitoring. The primary and secondary efficacy end points were acute PV isolation (PVI), PVI durability, and atrial arrhythmia recurrence., Results: In the 48-patient AF cohort (paroxysmal, 48%; persistent, 52%), lesion sets included PVI (n = 48; 1.2 applications/PV), posterior wall (n = 20; 3.6 applications/posterior wall), and mitral isthmus (n = 11; 2.9 applications/mitral isthmus). Lesions were acutely successful for all 187 of 187 PVs (100%), 20 of 20 posterior walls (100%), and 10 of 11 mitral isthmuses (91%). Pulse delivery time, left atrial catheter dwell time, and procedure time were 61.5 ± 32.8 seconds, 53.9 ± 26.5 minutes, and 87.8 ± 29.8 minutes, respectively. Remapping (43/48 patients [89.5%]) revealed that 158 of 169 PVs (93.5%) were durably isolated. The only complication was a drug-responsive pericarditis. The 1-year Kaplan-Meier estimates of freedom from atrial arrhythmia were 84.2% (paroxysmal AF) and 80.0% (persistent AF)., Conclusion: The single-shot spherical array PFA catheter can safely achieve durable lesions, translating into good clinical efficacy., Competing Interests: Disclosures Vivek Reddy reports receiving consulting fees (and equity) from Kardium Inc; and unrelated to this manuscript, he also serves as a consultant for and has equity in Ablacon, Acutus Medical, Affera-Medtronic, Anumana, Apama Medical–Boston Scientific, APN Health, Aquaheart, Atacor, Autonomix, Axon Therapies, Backbeat, BioSig, CardiaCare, Cardiofocus, CardioNXT/AFTx, Circa Scientific, CoRISMA, Corvia Medical, Dinova-Hangzhou DiNovA EP Technology, East End Medical, EPD-Philips, EP Frontiers, Epix Therapeutics–Medtronic, EpiEP, Eximo, Farapulse–Boston Scientific, Field Medical, Focused Therapeutics, HRT, Intershunt, Javelin, Keystone Heart, Laminar Medical, LuxMed, Medlumics, Middlepeak, Neutrace, Nuvera–Biosense Webster, Oracle Health, Restore Medical, Sirona Medical, SoundCath, Valcare; unrelated to this work, he has served as a consultant for Abbott, Adagio Medical, Append Medical, AtriAN, Biosense Webster, BioTel Heart, Biotronik, Boston Scientific, Cairdac, Cardionomic, CoreMap, Fire1, Gore & Associates, Impulse Dynamics, Medtronic, Novartis, Novo Nordisk, Philips, Pulse Biosciences; and unrelated to this work, he has equity in Atraverse, DRS Vascular, Manual Surgical Sciences, Newpace, Nyra Medical, Soundcath, Surecor, and Vizaramed. Petr Neuzil: grant support from Kardium Inc. Jacob Koruth: grant support and stock options from Kardium/Affera-Medtronic/Pulse Biosciences and Field Medical; consultant/grant support from Cardiofocus; consultant for Biosense Webster, Abbott, Boston Scientific and Medtronic. Mohit Turagam: consultant for Biosense Webster, Boston Scientific, Alta Thera; speaking honorarium: Sanofi, Medtronic. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Unlike conventional microsecond pulsed electrical fields that primarily target the cell membranes, nanosecond pulses are thought to primarily electroporate intracellular organelles. We conducted a comprehensive preclinical assessment of catheter-based endocardial nanosecond pulsed field ablation in swine., Methods: A novel endocardial nanosecond pulsed field ablation system was evaluated in a total of 25 swine. Using either a low-dose (5-second duration) or high-dose (15-second duration) strategy, thoracic veins and discrete atrial and ventricular sites were ablated. Predetermined survival periods were <1 (n=1), ≈2 (n=7), ≈7 (n=6), 14 (n=2), or ≈28 (n=9) days, and venous isolation was assessed before euthanasia. Safety assessments included evaluation of esophageal effects, phrenic nerve function, and changes in venous caliber. All tissues were subject to careful gross pathological and histopathologic examination., Results: All (100%) veins (13 low-dose, 34 high-dose) were acutely isolated, and all reassessed veins (6 low-dose, 15 high-dose) were durably isolated. All examined vein lesions (10 low-dose, 22 high-dose) were transmural. Vein diameters (n=15) were not significantly changed. Of the animals assessed for phrenic palsy (n=9), 3 (33%) demonstrated only transient palsy. There were no differences between dosing strategies. Thirteen mitral isthmus lesions were analyzed, and all 13 (100%) were transmural (depth, 6.4±0.4 mm). Ventricular lesions were 14.7±4.5 mm wide and 7.1±1.3 mm deep, with high-dose lesions deeper than low-dose (7.9±1.2 versus 6.2±0.8 mm; P =0.007). The esophagus revealed nontransmural adventitial surface lesions in 5 of 5 (100%) animals euthanized early (2 days) post-ablation. In the 10 animals euthanized later (14-28 days), all animals demonstrated significant esophageal healing-8 with complete resolution, and 2 with only trace fibrosis., Conclusions: A novel, endocardial nanosecond pulsed field ablation system provides acute and durable venous isolation and linear lesions. Transient phrenic injury and nontransmural esophageal lesions can occur with worst-case assessments suggesting limits to pulsed field ablation tissue selectivity and the need for dedicated assessments during clinical studies., Competing Interests: Dr Reddy is a consultant to Pulse Biosciences. Dr Koruth is a consultant to Pulse Biosciences and has received grant support from Pulse Biosciences. Dr Nies has received a scholarship from the German Research Foundation (Deutsche Forschungsgemeinschaft). Dr Linder is a contractor/consultant paid by Pulse Biosciences to perform the histological evaluation. J. Litt, R. Turovskiy, D.J. Danitz, and D.R. Uecker are paid employees of Pulse Biosciences with stock options. A comprehensive list of all financial disclosures (unrelated to this article) is included in the Supplemental Material. The other authors report no conflicts.

Background: Endocardial catheter-based pulsed field ablation (PFA) of the ventricular myocardium is promising. However, little is known about PFA's ability to target intracavitary structures, epicardium, and ways to achieve transmural lesions across thick ventricular tissue., Methods: A lattice-tip catheter was used to deliver biphasic monopolar PFA to swine ventricles under general anesthesia, with electroanatomical mapping, fluoroscopy and intracardiac echocardiography guidance. We conducted experiments to assess the feasibility and safety of repetitive monopolar PFA applications to ablate (1) intracavitary papillary muscles and moderator bands, (2) epicardial targets, and (3) bipolar PFA for midmyocardial targets in the interventricular septum and left ventricular free wall., Results: (1) Papillary muscles (n=13) were successfully ablated and then evaluated at 2, 7, and 21 days. Nine lesions with stable contact measured 18.3±2.4 mm long, 15.3±1.5 mm wide, and 5.8±1.0 mm deep at 2 days. Chronic lesions demonstrated preserved chordae without mitral regurgitation. Two targeted moderator bands were transmurally ablated without structural disruption. (2) Transatrial saline/carbon dioxide assisted epicardial access was obtained successfully and epicardial monopolar lesions had a mean length, width, and depth of 30.4±4.2, 23.5±4.1, and 9.1±1.9 mm, respectively. (3) Bipolar PFA lesions were delivered across the septum (n=11) and the left ventricular free wall (n=7). Twelve completed bipolar lesions had a mean length, width, and depth of 29.6±5.5, 21.0±7.3, and 14.3±4.7 mm, respectively. Chronically, these lesions demonstrated uniform fibrotic changes without tissue disruption. Bipolar lesions were significantly deeper than the monopolar epicardial lesions., Conclusions: This in vivo evaluation demonstrates that PFA can successfully ablate intracavitary structures and create deep epicardial lesions and transmural left ventricular lesions., Competing Interests: Disclosures Drs Koruth and Reddy have served as a consultant to and received grant support and equity from Affera-Medtronic. A comprehensive list of all financial disclosures (unrelated to this article) is included in the Supplemental Material. Dr Nies has received a scholarship from the German Research Foundation (Deutsche Forschungsgemeinschaft). The other authors report no conflicts.

Aims: Pulsed field ablation (PFA) has significant advantages over conventional thermal ablation of atrial fibrillation (AF). This first-in-human, single-arm trial to treat paroxysmal AF (PAF) assessed the efficiency, safety, pulmonary vein isolation (PVI) durability and one-year clinical effectiveness of an 8 Fr, large-lattice, conformable single-shot PFA catheter together with a dedicated electroanatomical mapping system., Methods and Results: After rendering the PV anatomy, the PFA catheter delivered monopolar, biphasic pulse trains (5-6 s per application; ∼4 applications per PV). Three waveforms were tested: PULSE1, PULSE2, and PULSE3. Follow-up included ECGs, Holters at 6 and 12 months, and symptomatic and scheduled transtelephonic monitoring. The primary and secondary efficacy endpoints were acute PVI and post-blanking atrial arrhythmia recurrence, respectively. Invasive remapping was conducted ∼75 days post-ablation. At three centres, PVI was performed by five operators in 85 patients using PULSE1 (n = 30), PULSE2 (n = 20), and PULSE3 (n = 35). Acute PVI was achieved in 100% of PVs using 3.9 ± 1.4 PFA applications per PV. Overall procedure, transpired ablation, PFA catheter dwell and fluoroscopy times were 56.5 ± 21.6, 10.0 ± 6.0, 19.1 ± 9.3, and 5.7 ± 3.9 min, respectively. No pre-defined primary safety events occurred. Upon remapping, PVI durability was 90% and 99% on a per-vein basis for the total and PULSE3 cohort, respectively. The Kaplan-Meier estimate of one-year freedom from atrial arrhythmias was 81.8% (95% CI 70.2-89.2%) for the total, and 100% (95% CI 80.6-100%) for the PULSE3 cohort., Conclusion: Pulmonary vein isolation (PVI) utilizing a conformable single-shot PFA catheter to treat PAF was efficient, safe, and effective, with durable lesions demonstrated upon remapping., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Pulsed field ablation (PFA) is a novel energy form for the catheter ablation of cardiac arrhythmias, which uses electrical fields to mediate myocardial death via irreversible electroporation and other modalities. It is believed to offer relative tissue specificity, lowering - or even eliminating - the risk of complications associated with thermal energy, such as atrio-oesophageal fistulas. The proposed superior safety profile compared to thermal ablation has contributed to the enthusiastic implementation of PFA into clinical practice and is supported by early preclinical and clinical data. However, data about the effects of PFA on the oesophagus remain limited. This organ's susceptibility to PFA has important clinical ramifications and there are two highly relevant questions. First, is the oesophagus absolutely spared by PFA or is there susceptibility to injury at higher field strengths? Second, if oesophageal injury can occur, can atrio-oesophageal fistulas ensue? The aim of this article is to provide a literature review on the effects of PFA on the oesophagus and to address these questions based on the data described., Competing Interests: Disclosure: MN has received a scholarship from the German Research Foundation (Deutsche Forschungsgemeinschaft). JSK has received consultancy fees from Abbott, Biosense Webster, Boston Scientific, Cardiofocus and Medtronic, research grants from Affera, Cardiofocus and Pulse Bioscience and stock options from Affera. All other authors have no conflicts of interest to declare., (Copyright © The Author(s), 2024. Published by Radcliffe Group Ltd.)

Competing Interests: Funding Support and Author Disclosures Dr Nies has received a scholarship from the German Research Foundation (Deutsche Forschungsgemeinschaft). Dr Koruth has served as a consultant for, and has received grant support from Cardiofocus; has served as a consultant for Abbott, Boston Scientific, Biosense Webster, and Medtronic; has received grant support and stock options from Affera-Medtronic; has received grant support from Pulse Bioscience. Dr Reddy has served as a consultant to, and received equity from Affera-Medtronic; unrelated to this manuscript, he also serves as a consultant for and has equity in Ablacon, Acutus Medical, Apama Medical-Boston Scientific, Anumana, APN Health, Aquaheart, Atacor, Autonomix, Axon Therapies, Backbeat, BioSig, CardiaCare, CardioNXT / AFTx, Circa Scientific, CoRISMA, Corvia Medical, Dinova-Hangzhou DiNovA EP Technology, East End Medical, EPD-Philips, EP Frontiers, Epix Therapeutics-Medtronic, EpiEP, Eximo, Farapulse-Boston Scientific, Field Medical, Focused Therapeutics, HRT, Intershunt, Javelin, Kardium, Keystone Heart, LuxMed, Medlumics, Middlepeak, Neutrace, Nuvera-Biosense Webster, Oracle Health, Restore Medical, Sirona Medical, SoundCath, Valcare; unrelated to this work, has served as a consultant for Abbott, AtriAN, Biosense-Webster, BioTel Heart, Biotronik, Boston Scientific, Cairdac, Cardiofocus, Cardionomic, CoreMap, Fire1, Gore & Associates, Impulse Dynamics, Medtronic, Novartis, Philips, Pulse Biosciences; and has equity in DRS Vascular, Manual Surgical Sciences, Newpace, Nyra Medical, Surecor, and Vizaramed. All other authors reported that they have no relationships relevant to the contents of this paper to disclose.

Importance: In treating atrial fibrillation, pulsed field ablation (PFA) is a novel energy modality with comparable efficacy to conventional thermal ablation, such as radiofrequency ablation (RFA), but with the benefit of some preferentiality to myocardial tissue ablation. Studies have demonstrated important safety advantages, including the absence of esophageal injury or pulmonary vein stenosis and only rare phrenic nerve injury. However, there is emerging evidence of coronary artery vasospasm provoked by PFA., Objective: To compare the incidence and severity of left circumflex arterial vasospasm between PFA and RFA during adjacent ablation along the mitral isthmus., Design, Setting, and Participants: This prospective cohort study enrolled consecutive adult patients receiving first-ever PFA or RFA of the mitral isthmus during catheter ablation of atrial fibrillation in 2022 with acute follow-up at a single referral European center., Exposure: A posterolateral mitral isthmus line was created using either a multielectrode pentaspline PFA catheter (endocardial ablation) or a saline-irrigated RFA catheter. Simultaneous diagnostic coronary angiography was performed before, during, and after catheter ablation. Nitroglycerin was planned for spasm persisting beyond 20 minutes or for significant electrocardiographic changes., Main Outcomes and Measures: The frequency and severity of left circumflex arterial vasospasm was assessed and monitored, as were time to remission and any need for nitroglycerin administration., Results: Of 26 included patients, 19 (73%) were male, and the mean (SD) age was 65.5 (9.3) years. Patients underwent either PFA (n = 17) or RFA (n = 9) along the mitral isthmus. Coronary spasm was observed in 7 of 17 patients (41.2%) undergoing PFA: in 7 of 9 (77.8%) when the mitral isthmus ablation line was situated superiorly and in 0 of 8 when situated inferiorly. Conversely, coronary spasm did not occur in any of the 9 patients undergoing RFA. Of 5 patients in whom crossover PFA was performed after RFA failed to achieve conduction block, coronary spasm occurred in 3 (60%). Most instances of spasm (9 of 10 [90%]) were subclinical, with 2 (20%) requiring nitroglycerin administration. The median (range) time to resolution of spasm was 5 (5-25) minutes., Conclusion and Relevance: When creating a mitral isthmus ablation line during catheter ablation of atrial fibrillation, adjacent left circumflex arterial vasospasm frequently occurred with PFA and not RFA but was typically subclinical.