Toni Brešković

Background: Thromboembolic events, though infrequent, remain a significant complication of atrial fibrillation (AF) ablation, largely related to endothelial damage. Cryoballoon (CB) and radiofrequency ablation can induce pro-coagulant responses, whereas pulsed-field ablation (PFA), a novel non-thermal electroporation-based technique, has shown tissue selectivity with potential endothelial-sparing effects. Methods: We aimed to compare PFA and second-generation CB ablation regarding endothelial injury in patients with paroxysmal AF. In this single-center prospective observational study, 25 patients with paroxysmal drug-refractory AF underwent pulmonary vein isolation using either a pentaspline PFA catheter (n = 14) or a second-generation CB catheter (n = 11). Circulating von Willebrand factor antigen (vWF) levels were assessed before and after ablation as a biomarker of endothelial damage, alongside routine laboratory and echocardiographic parameters. Procedural characteristics were also analyzed. Results: Baseline demographic, clinical, and echocardiographic data were comparable between groups. PFA was associated with significantly shorter skin-to-skin procedure time (59 vs. 94 min, p = 0.005) and left atrial dwell time (44 vs. 79 min, p < 0.001) compared with CB ablation. Importantly, vWF levels decreased significantly after PFA (−7.6%, p = 0.007), while CB ablation showed a non-significant increase (+9.5%, p = 0.155). The between-group difference in percent change of vWF was statistically significant (−5.6% vs. +8.3%, p = 0.006). Conclusions: PFA was associated with reduced endothelial injury and shorter procedural times compared with CB ablation, suggesting a potential advantage in lowering thromboembolic risk. These findings support the concept of PFA as an “endothelial sparing” ablation modality. However, the PFA procedure was associated with a significantly greater extent of myocardial injury, as reflected in circulating high-sensitivity cardiac troponin T values, compared to CB ablation (p = 0.007). Larger, randomized studies are warranted to confirm these results and evaluate long-term clinical outcomes.

Thromboembolic events, though infrequent, remain a significant complication of atrial fibrillation (AF) ablation, largely related to endothelial damage. Cryoballoon (CB) and radiofrequency ablation can induce pro-coagulant responses, whereas pulsed-field ablation (PFA), a novel non-thermal electroporation-based technique, has shown tissue selectivity with potential endothelial-sparing effects. We aimed to compare PFA and second-generation CB ablation regarding endothelial injury in patients with paroxysmal AF. In this single-center prospective observational study, 25 patients with paroxysmal drug-refractory AF underwent pulmonary vein isolation using either a pentaspline PFA catheter (n=14) or a second-generation CB catheter (n=11). Circulating von Willebrand factor antigen (vWF) levels were assessed before and after ablation as a biomarker of endothelial damage, alongside routine laboratory and echocardiographic parameters. Procedural characteristics were also analyzed. Baseline demographic, clinical, and echocardiographic data were comparable between groups. PFA was associated with significantly shorter skin-to-skin procedure time (59 vs. 94 min, p=0.005) and left atrial dwell time (44 vs. 79 min, p<0.001) compared with CB ablation. Importantly, vWF levels decreased significantly after PFA (−7.6%, p=0.007), while CB ablation showed a non-significant increase (+9.5%, p=0.155). The between-group difference in percent change of vWF was statistically significant (−5.6% vs. +8.3%, p=0.006). PFA was associated with reduced endothelial injury and shorter procedural times compared with CB ablation, suggesting a potential advantage in lowering thromboembolic risk. These findings support the concept of PFA as an “endothelial-sparing” ablation modality. Larger, randomized studies are warranted to confirm these results and evaluate long-term clinical outcomes.

BACKGROUND: Pulsed field ablation (PFA) is a promising treatment for atrial fibrillation. We report 1-year freedom from atrial arrhythmia outcomes using monopolar PFA delivered through 3 commercial, contact force–sensing focal catheters. METHODS: ECLIPSE AF (Safety & Clinical Performance Study of Catheter Ablation With the Centauri System for Patients With Atrial Fibrillation; NCT04523545) was a prospective, single-arm, multicenter study evaluating acute and chronic safety and performance using the CENTAURI system to deliver focal PFA with TactiCath SE, StablePoint, and ThermoCool ST. Patients with paroxysmal or persistent atrial fibrillation underwent pulmonary vein (PV) isolation under deep sedation or general anesthesia and returned for remapping at 90 days to evaluate chronic durability. Freedom from atrial arrhythmia was evaluated continuously through 12 months using standard rhythm monitoring for symptomatic episodes and 24-hour Holter at 6 and 12 months. RESULTS: Eighty-two patients (74% male, 51.2% paroxysmal, and 58.5% deep sedation) were treated. PV isolation was achieved in 100% of targeted veins (322/322) with first-pass isolation in 92.2% (297/322). There were 4 primary safety events in 4 patients (4.9%, 4/82); 1 nonembolic stroke due to exacerbated cardiac tamponade secondary to catheter perforation and 3 hemorrhagic vascular access complications. There were no incidences of adverse event fistula, diaphragmatic paralysis, myocardial infarction, pericarditis, thromboembolism, PV stenosis, transient ischemic attack, or death. Eighty patients (98%) underwent remapping. Optimized PFA cohorts 3, 4, and 5 showed per-patient isolation rates of 60%, 73%, and 81% and per-PV isolation rates of 84%, 90%, and 92%, respectively. One-year freedom from atrial arrhythmia was 80.2% (95% CI, 69.7%–87.4%) for the entire patient sample, including 41 patients who underwent repeat focal PFA with the CENTAURI system at remapping. CONCLUSIONS: This study demonstrated that optimization of focal PFA with 3 contact force–sensing, solid-tip ablation catheters resulted in the progressive improvement of PV isolation durability at 3-month remapping and high freedom from atrial arrhythmia survival rates, providing a promising focal PFA treatment option integrated with current ablation workflows.

Introduction: 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.Methods: 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.Results: 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.Conclusion: 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.

Background: Focal pulsed field ablation (fPFA) has emerged as a versatile and innovative strategy for ablating atrial tachyarrhythmias (1). The primary objective of this study is to present the short-term safety characteristics, feasibility and procedural outcomes of fPFA in the management of organised atrial tachyarrhythmias. This report focuses on the commercial use of an innovative pulsed field ablation (PFA) generator, utilized in conjunction with commercially available focal, solid-tip ablation catheters, and complemented by 3D electro-anatomical mapping (3D-EAM). Methods: Patients with organised atrial tachycardia treated using fPFA between August 2022 and September 2023 at our center were included in this retrospective analysis. Tachycardia mechanisms were identified with high-definition, multi-electrode mapping catheter paired with 3D-EAM system. Ablation lines, when targeting macro-reentrant arrhythmias were strategicaly positioned to adress critical isthmi when recognised or they were empirically placed between the anatomical obstacles ( including LA roof, anterior, mitral isthmus, upper septal and cavotricuspid line as deemed appropriate). Positioning of the fPFA catheter was guided by 3D-EAM, intracardiac ultrasound, and fluoroscopy (Figure 1). Bidirectional block verification was performed using standard criteria to assess acute procedural success. Glyceryl trinitrate boluses were administered prior to ablation in proximity to coronary arteries. Results: In a cohort of 36 patients (median age 62 years; 12 females), we effectively mapped and treated a total of 51 distinct organised atrial tachyarrhythmias. These included 18 typical flutters, 3 roof-dependent macro-reentries, 4 posterior-wall micro-reentries, 15 peri-mitral macro-reentries, 8 anterior-wall micro-reentries and 3 biatrial macro-reentries via Bachman bundle. Our ablation strategy involved creating 21 cavotricuspid isthmus lines, 3 roof lines, 18 posterior wall lines, 11 anterior lines, 8 septal lines, and 15 mitral isthmus lines (Figure 2). Impressively, first-pass acute isolation with bidirectional block was achieved in 93% (54 of 58) of isthmus ablations and 94% (17 of 18) of left posterior wall lines. No ST segment alterations or other complications were observed during the periprocedural period. Conclusion: In our cohort fPFA proved as a feasible, effective, and safe approach for treating organised atrial tacharrhythmias. The primary reason for designating this setup as our preferred choice for redo procedures lies in its versatility in addressing a wide range of arrhythmias. As ultra-fast pulmonary vein isolation (PVI) procedures become more prevalent with the expansion of PFA, the demand for an ideal setup capable of effectively targeting various substrates will become even more pronounced (2). Notably, our findings suggest superior suitability and efficacy when compared to bulkier, single-shot design PFA devices (3).Figure 1Figure 2

Background/Introduction: Pulsed field ablation (PFA) is emerging as a safe and effective alternative energy modality for cardiac ablation. Data have shown that while tissue contact is critical for PFA, the amount of contact force is less important. Single-shot catheters have shown comparable results to current thermal methods for pulmonary vein isolation (PVI), however, are limited to anatomical-based ablation strategies and have limited ability to detect tissue contact. The investigational QuickShot™ large-area focal catheter (Galvanize Therapeutics, Redwood City, CA) combines high-density mapping with large-area focal ablation guided by contact detection. Purpose: The QuickShot PEF-AF study was a prospective, single-arm, first-in-human study performed at a single European center to evaluate the safety and performance of the QuickShot catheter (see Figure 1, panel A) combined with the CE-marked CENTAURI™ System (Galvanize Therapeutics, Figure 1, panel B) for catheter ablation of atrial fibrillation (AF). Methods: Subjects with paroxysmal or persistent AF underwent a PVI procedure under deep sedation (fentanyl, midazolam, propofol) guided by Rhythmia™ HDx (Boston Scientific, Marlborough, MA, Figure 1, panel D). Irrigation was set to a constant 6 mL/min during the procedure. Focal, monopolar, biphasic PFA lesions were delivered asynchronously at 33 Amps and a 10 mm inter-lesion spacing (center to center with 10 mm lesion tag size). Catheter-tissue contact was confirmed by ICE/fluoroscopy and a novel impedance-based contact detection system (Figure 1, panel C). The acute performance endpoint was PVI, assessed by entrance and exit block using high-density mapping. Procedural safety assessments included microbubble detection via ICE, induction of VT/VF, muscle stimulation, phrenic nerve function, and NIHSS post-procedure. Results: Twenty (20) subjects (60% PAF, 60 ± 12 years, 75% male, 4.3 ± 0.52 cm LA AP diameter) were enrolled and treated. Acute PVI was achieved in 100% of patients and targeted PVs (82/82), with first-pass isolation in 88% of targeted PVs. The PVI time was 31 ± 10 min with 46.7 ± 11.4 PFA applications. There were no device- or procedure-related adverse events, and no documented incidence of microbubble formation, arrhythmia induction, muscle stimulation, phrenic nerve dysfunction, esophageal injury, or change in NIHSS post-procedure. Conclusion: The QuickShot catheter enables safe and effective large-area focal PFA for subjects requiring PVI. The catheter design enables efficient and flexible focal lesion placement with the ability to ensure adequate apposition to targeted tissues using its novel contact detection algorithm. Future studies will investigate the use of this novel catheter for PFA strategies beyond PVI.