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Background: Pulsed field ablation is a novel nonthermal cardiac ablation modality using ultra-rapid electrical pulses to cause cell death by a mechanism of irreversible electroporation. Unlike the traditional ablation energy sources, pulsed field ablation has demonstrated significant preferentiality to myocardial tissue ablation, and thus avoids certain thermally mediated complications. However, its safety and effectiveness remain unknown in usual clinical care., Methods: MANIFEST-PF (Multi-National Survey on the Methods, Efficacy, and Safety on the Post-Approval Clinical Use of Pulsed Field Ablation) is a retrospective, multinational, patient-level registry wherein patients at each center were prospectively included in their respective center registries. The registry included all patients undergoing postapproval treatment with a multielectrode 5-spline pulsed field ablation catheter to treat atrial fibrillation (AF) between March 1, 2021, and May 30, 2022. The primary effectiveness outcome was freedom from clinical documented atrial arrhythmia (AF/atrial flutter/atrial tachycardia) of ≥30 seconds on the basis of electrocardiographic data after a 3-month blanking period (on or off antiarrhythmic drugs). Safety outcomes included the composite of acute (<7 days postprocedure) and latent (>7 days) major adverse events., Results: At 24 European centers (77 operators) pulsed field ablation was performed in 1568 patients with AF: age 64.5±11.5 years, female 35%, paroxysmal/persistent AF 65%/32%, CHA 2 DS 2 -VASc 2.2±1.6, median left ventricular ejection fraction 60%, and left atrial diameter 42 mm. Pulmonary vein isolation was achieved in 99.2% of patients. After a median (interquartile range) follow-up of 367 (289-421) days, the 1-year Kaplan-Meier estimate for freedom from atrial arrhythmia was 78.1% (95% CI, 76.0%-80.0%); clinical effectiveness was more common in patients with paroxysmal AF versus persistent AF (81.6% versus 71.5%; P =0.001). Acute major adverse events occurred in 1.9% of patients., Conclusions: In this large observational registry of the postapproval clinical use of pulsed field technology to treat AF, catheter ablation using pulsed field energy was clinically effective in 78% of patients with AF., Competing Interests: Disclosures Dr Reddy reports receiving consulting fees (and equity—now divested) from Farapulse Inc. and is a consultant for Boston Scientific Inc; unrelated to this manuscript, Dr Reddy also 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, 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 AtriAN, Biosense-Webster, BioTel Heart, Biotronik, Cairdac, Cardiofocus, Cardionomic, CoreMap, Fire1, Gore & Associates, Impulse Dynamics, Medtronic, Novartis, Philips, Pulse Biosciences; and has equity in Manual Surgical Sciences, Newpace, Nyra Medical, Surecor, and Vizaramed. Dr Schmidt reports receiving speaker’s fees and research grants from Boston Scientific/Farapulse, Medtronic, Biosense Webster, and Abbott. Dr Reichlin reports research grants from the Swiss National Science Foundation, the Swiss Heart Foundation, and the sitem insel Support Fund. Speaker/consulting honoraria or travel support from Abbott/SJM, Bayer, Biosense Webster, Biotronik, Boston Scientific, Daiichi Sankyo, Medtronic, and Pfizer-BMS. Support for his institution’s fellowship programme from Abbott/SJM, Biosense Webster, Biotronik, Boston Scientific, and Medtronic. Dr Roten reports receiving speaker honoraria from Abbott/SJM, consulting honoraria from Medtronic, and research funding to the institution from Medtronic. Dr Neven reports speaker’s fees from Farapulse, Inc. Dr Metzner reports research grant and fees from Farapulse. Dr Rollin reports receiving research grant from Farapulse. Dr Lemoine reports receiving research grant from Farapulse. Dr Hansen reports receiving speaker fees and grant support from Biosense Webster, and Medtronic. Dr Blaauw reports receiving research grants from Medtronic and Atricure and consulting fees from Abbott, Biosense Webster, Boston Scientific. Dr Sommer reports member of the advisory board for Abbott, Biosense Webster, Boston Scientific, and Medtronic. Dr Anic reports receiving consultant fees from Farapulse Inc., Boston Scientific Inc., Galaxy Medical Inc., Biosense Webster, and performs contracted research for Farapulse Inc., Boston Scientific Inc., Galaxy Medical Inc., and Biosense Webster. Dr Anselme reports receiving consulting fees from Boston Scientific, Medtronic, and Microport CRM. Dr Boveda reports receiving consulting fees from Medtronic, Boston Scientific, Microport, Zoll, and BMS. Dr Deneke reports receiving speaker honoraria from Galaxy Medical, Abbott, and Biotronik, being a consultant to Farapulse, and serving on a Clinical Events Committee for Boston Scientific. Dr Willems reports receiving grants and personal fees from Abbott, Boston Scientific, Medtronic, and personal fees from Boehringer Ingelheim, Brystol Myers Squibb, Bayer Vital, Accutus, Daiichi, and Farapulse Inc. Dr Gunawardene reports grants from Farapulse Inc. and Abbott. Dr Tilz reports receiving consulting fees from Boston Scientific, Abbott Medical, Biotronik, Biosense Webster and speaker honorarium from Boston Scientific, Abbott Medical, Biotronik, and Biosense Webster. Dr Heeger received travel grants and research grants by Boston Scientific, Lifetech, Biosense Webster, and Cardiofocus and Speaker´s Honoraria from Boston Scientific, Lifetech. Biosense Webster, Bayer, and Cardiofocus. He is a consultant of Medtronic, Lifetech, Boston Scientific, Biosense Webster, and Cardiofocus. Dr Scheer reports receiving an educational grant from Farapulse Inc. and is a consultant for Boston Scientific Inc. Dr Wakili reports receiving consultant fees and travel expenses from Boston Scientific and Biotronik; investigator-initiated funding for research projects (initiated by him) from Bristol-Myers Squibb, Pfizer, and Boston Scientific; and speaking honoraria from Boston Scientific, Biotronik, and Medtronic. Dr Steven reports receiving speaking fees from Pfizer, Bayer, Abbott, Johnson & Johnson, and Medtronic; grants from Abbott, Johnson & Johnson, and Boston Scientific; and consulting fees from Boston Scientific and Johnson & Johnson. Dr Sultan reports receiving lecture and consulting honoraria from Medtronic, Abbott, and Bayer. Dr Kautzner reports personal fees from Bayer, Biosense Webster, Boehringer Ingelheim, Medtronic, and Abbott for participation in scientific advisory boards, and has received speaker honoraria from Bayer, Biosense Webster, Biotronik, Boehringer Ingelheim, CathVision, Medtronic, Mylan, Pfizer, ProMed, and Abbott. Dr Jais reports receiving equity from Farapulse and consulting fees and grant from Boston Scientific. Dr Derval reports receiving consulting fees from Boston scientific. Dr Chun reports receiving speaker’s fees and research grants from Boston Scientific/Farapulse, Medtronic, Biosense Webster, and Abbott. Dr Neuzil reports receiving grants from the Ministry of Health, Czech Republic, DRO (NHH, 00023884). Dr Manninger reports receiving speaker fees from Bayer, Biosense Webster, Biotronik, Amomed, AOP Orphan, Boston Scientific, Daiichi Sankyo, BMS/Pfizer and research grants from Biosense Webster and Abbott. All remaining authors have declared no conflict of interest.

Objectives: The results from the recent Targeted Temperature Management trial raised the question whether cooling or merely the avoidance of fever mediates better neurologic outcome in resuscitated patients. As temperature per se is a major determinant of cardiac function, we characterized the effects of hyperthermia (40.5°C), normothermia (38.0°C), and mild hypothermia (33.0°C) on left ventricular contractile function in healthy pigs and compared them with dobutamine infusion., Design: Animal study., Setting: Large animal facility, Medical University of Graz, Graz, Austria., Subjects: Nine anesthetized and mechanically ventilated closed-chest Landrace pigs (67 ± 2 kg)., Interventions: Core body temperature was controlled using an intravascular device. At each temperature step, IV dobutamine was titrated to double maximum left ventricular dP/dt (1.8 ± 0.1 µg/kg/min at normothermia). Left ventricular pressure-volume relationships were assessed during short aortic occlusions. Left ventricular contractility was assessed by the calculated left ventricular end-systolic volume at an end-systolic left ventricular pressure of 100 mm Hg., Measurements and Main Results: Heart rate (98 ± 4 vs 89 ± 4 vs 65 ± 2 beats/min; all p < 0.05) and cardiac output (6.7 ± 0.3 vs 6.1 ± 0.3 vs 4.4 ± 0.2 L/min) decreased with cooling from hyperthermia to normothermia and mild hypothermia, whereas left ventricular contractility increased (left ventricular end-systolic volume at a pressure of 100 mm Hg: 74 ± 5 mL at hyperthermia, 52 ± 4 mL at normothermia, and 41 ± 3 mL at mild hypothermia; all p < 0.05). The effect of cooling on left ventricular end-systolic volume at a pressure of 100 mm Hg (hyperthermia to normothermia: -28% ± 3% and normothermia to mild hypothermia: -20% ± 5%) was of comparable effect size as dobutamine at a given temperature (hyperthermia: -28% ± 4%, normothermia: -27% ± 6%, and mild hypothermia: -27% ± 9%)., Conclusions: Cooling from hyperthermia to normothermia and from normothermia to mild hypothermia increased left ventricular contractility to a similar degree as a significant dose of dobutamine in the normal porcine heart. These data indicate that cooling can reduce the need for positive inotropes and that lower rather than higher temperatures are appropriate for the resuscitated failing heart.

Background: This study aimed to determine 5-year efficacy of catheter ablation for persistent atrial fibrillation (AF) using AF termination as a procedural end point., Methods and Results: One hundred fifty patients (57±10 years) underwent persistent AF ablation using a stepwise ablation approach (pulmonary vein isolation, electrogram-guided, and linear ablation) with the desired procedural end point being AF termination. Repeat ablation was performed for recurrent AF or atrial tachycardia. AF was terminated by ablation in 120 patients (80%). Arrhythmia-free survival rates after a single procedure were 35.3%±3.9%, 28.0%±3.7%, and 16.8%±3.2% at 1, 2, and 5 years, respectively. Arrhythmia-free survival rates after the last procedure (mean 2.1±1.0 procedures) were 89.7%±2.5%, 79.8%±3.4%, and 62.9%±4.5%, at 1, 2, and 5 years, respectively. During a median follow-up of 58 (interquartile range, 43-73) months after the last ablation procedure, 97 of 150 (64.7%) patients remained in sinus rhythm without antiarrhythmic drugs. Another 14 (9.3%) patients maintained sinus rhythm after reinitiation of antiarrhythmic drugs, and an additional 15 (10.0%) patients regressed to paroxysmal recurrences only. Failure to terminate AF during the index procedure (hazard ratio 3.831; 95% confidence interval, 2.070-7.143; P<0.001), left atrial diameter≥50 mm (hazard ratio 2.083; 95% confidence interval, 1.078-4.016; P=0.03), continuous AF duration≥18 months (hazard ratio 1.984; 95% confidence interval, 1.024-3.846; P<0.04), and structural heart disease (hazard ratio 1.874; 95% confidence interval, 1.037-3.388; P=0.04) predicted arrhythmia recurrence., Conclusions: In patients with persistent AF, an ablation strategy aiming at AF termination is associated with freedom from arrhythmia recurrence in the majority of patients over a 5-year follow-up period. Procedural AF nontermination and specific baseline factors predict long-term outcome after ablation., (© 2014 American Heart Association, Inc.)