Performing Pulmonary Vein Isolation Research Articles

First comparison of single-tip versus single-shot pulsed field ablation for pulmonary vein isolation in paroxysmal atrial fibrillation: interim analysis of a randomized trial

Abstract Background Non-thermal pulsed field ablation (PFA) is an emerging technology to perform pulmonary vein isolation (PVI) for atrial fibrillation (AF). Different PFA systems are available, but no comparative data exist. Purpose Randomized trial to compare single-tip versus single-shot PFA for initial PVI in paroxysmal AF patients. Methods In this single-center trial, paroxysmal AF patients are prospectively enrolled and 1:1 randomized in the single-tip or single-shot PFA group. Single-tip PVI is performed using a PFA generator and a 3.5mm contact-force enabled ablation catheter guided by 3D mapping system. The pulsed electric field dosing is 25 Ampere (A) (anterior) and 22 A (posterior), respectively. In the single-shot PVI group, a 31 or 35mm pentaspline PFA catheter is used for fluoroscopy-guided PVI. Eight PFA applications (2.0 kV) are applied per PV. In this interim analysis, acute efficacy, safety and short term clinical outcome within the 3 months blanking period were assessed. A subset of patients underwent cerebral MRI to detect silent lesions. Results To date, 50 patients were enrolled and underwent PVI in conscious sedation (25 single-tip, 25 single-shot, 63 ± 5 years, 42% female, CHA2DS2-VASc 2 [1-3]). There were no differences in baseline characteristics. Acute PVI was achieved in 100%. In the single-tip group, total procedure time was significantly longer (125 ± 31 min vs. 44 ± 12 min, p <0.001) and fluoroscopy time was significantly shorter (4 ± 2 min vs. 15 ± 6 min, p <0.001) as compared to the single-shot group. One groin hematoma was noted in the single-shot group. In the single-tip group, 1 aneurysm spurium was detected and 1 pericardial tamponade requiring drainage resulted from coughing during single-tip PFA while no real-time visualization of the catheter was available. No permanent sequelae occurred. There were no PFA specific complications and no cerebral embolisms were detected in all 14 MRI scans. At 3 months, 92% (single-shot group) and 80% in the single-tip group were free from arrhythmia (p=0.42). AF recurrences in the blanking period occurred in 2 patients in the single-shot group and in 5 patients in the single-tip group after a median of 2 [1-5] days following the procedure. Conclusions In this interim analysis of a randomized trial, single-shot or single-tip PFA for PVI both demonstrated high acute efficacy and a favourable 3 months clinical outcome. Procedural time was significantly longer in the single-tip PFA group. No silent lesions were detected in cerebral MRI. Non-availability of real-time visualization and contact-force information of the single-tip ablation catheter during energy application is a current technical limitation that could be associated with complications.

Comparative analysis of clinical outcomes in repeat ablation for recurrent atrial tachyarrhythmia following initial pulmonary vein isolation with pulsed-field ablation and cryoballoon ablation

Abstract Background While pulsed-field ablation (PFA) holds promise for the initial catheter ablation performing pulmonary vein (PV) isolation (PVI) in patients with atrial fibrillation (AF), a repeat procedure remains necessary for those experiencing recurrent atrial tachyarrhythmia (ATA). This study aimed to evaluate the clinical outcomes of repeat procedures following the initial PFA in patients with recurrent ATA by comparing that following the initial CBA. Methods Patients who underwent a second ablation for recurrent ATA following initial PVI with pentaspline PFA or cryoballoon ablation (CBA) were included. Repeat ablation utilized radiofrequency current ablation with three-dimensional mapping guidance, involving repeat PVI combined with linear ablations when necessary. Acute data, such as documented arrhythmia before the repeat procedure, the number of reconnected PVs, procedural characteristics, and clinical follow-up, were analyzed. Results In total, 110 patients underwent initially successful PVI with PFA (N = 51) and CBA (N = 59), followed by a repeat procedure for recurrent ATA with a mean time interval of 365±299 days between the two procedures. The primary indication at the repeat procedure was atrial tachycardia (AT) in the PFA group (N = 27, 53%) and AF in the CBA group (N = 47, 80%). The overall PV reconnection rate per vein was 22.1%, with no significant difference between the two groups (19.1% in PFA vs. 24.7% in CBA, P = 0.16). Repeat PVI was successfully performed in all patients with PV reconnection (41.2% in PFA vs. 55.9% in CBA, P = 0.12). PV reconnection was most commonly found at the right inferior PV in both groups (25.5% vs. CBA; 32.2%, P = 0.44). Additional substrate modification was conducted in 76.5% of the PFA group and 74.6% in the CBA group, respectively (P = 0.82). The mean follow-up period was 349±280 days. The Kaplan-Meier curve indicated no statistical significance in the 1-year arrhythmia-free survival after the repeat procedure (62.4% in PFA vs. and 73.0% in CBA group, P = 0.54, Figure). Conclusion Comparable lesion durability between the initial PVI with PFA and CBA was unveiled during the repeat ablation. The second ablation for recurrent arrhythmia following initial PFA demonstrated a favorable clinical success rate at one year after the subsequent procedure, showing no significant difference compared to repeat ablation subsequent to CBA.arrhythmia-free survival after the repe

Comparing pulsed field electroporation and radiofrequency ablation for the treatment of paroxysmal atrial fibrillation: design and rationale of the BEAT PAROX-AF randomized clinical trial.

Using thermal-based energy sources [radiofrequency (RF) energy/cryo energy] for catheter ablation is considered effective and safe when performing pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (AF). However, treatment success remains limited and complications can occur due to the propagation of thermal energy into non-target tissues. We aim to compare pulsed field ablation (PFA) with RF ablation in terms of efficacy and safety for patients with drug-resistant paroxysmal AF. The BEAT PAROX-AF trial is a European multicentre, superiority, open-label randomized clinical trial in two parallel groups. A total of 292 participants were recruited in 9 high-volume European clinical centres in 5 countries. Patients with paroxysmal AF were randomized to PFA (FARAPULSE Endocardial Ablation System©, Boston Scientific) or RF using the CLOSE protocol with contact force sensing catheter (SmartTouch© catheter and CARTO© Biosense Webster). The primary endpoint will be the 1-year recurrence of atrial arrhythmia, and the major secondary safety endpoint will be the occurrence of acute (<7 days) procedure-related serious adverse events, or pulmonary vein stenosis, or atrio-oesophageal fistula up to 12 months. Additionally, five sub-studies investigate the effect of PFA on oesophageal safety, cerebral lesions, cardiac autonomic nervous system, durability of PVI as assessed during redo ablation procedures, and atrial and ventricular function. The study began on 27 December 2021 and concluded recruitment on 17 January 2024. Results will be available in mid-2025. The BEAT PAROX-AF trial aims to provide critical insights into the optimal treatment approach for patients with paroxysmal AF.

Determination of Continuity Index Values in Atrial Fibrillation Ablation with Proactive Esophageal Cooling.

Radiofrequency (RF) ablation to perform pulmonary vein isolation (PVI) for the treatment of atrial fibrillation involves some risk to collateral structures, including the esophagus. Proactive esophageal cooling using a dedicated device has been granted marketing authorization by the Food and Drug Administration (FDA) to reduce the risk of ablation-related esophageal injury due to RF cardiac ablation procedures, and more recent data also suggest that esophageal cooling may contribute to improved long-term efficacy of treatment. A mechanistic underpinning explaining these findings exists through the quantification of lesion placement contiguity defined as the Continuity Index (CI). Kautzner et al. quantified the CI by the order of lesion placement, such that whenever a lesion is placed non-adjacent to the prior lesion, the CI is incremented by the number of segments the catheter tip has moved over. To facilitate real-time calculation of the CI and encourage further adoption of this instrument, we propose a modification in which the placement of non-adjacent lesions increments the CI by only one unit, avoiding the need to count potentially nebulous markers of atrial segmentation. The objective of this protocol is to describe the methods of calculating the CI both prospectively during real-time PVI cases and retrospectively using recorded case data. A comparison of the results obtained between cases that utilized proactive esophageal cooling and cases that used luminal esophageal temperature (LET) monitoring is then provided.

Atrial Fibrillation Ablation: Current Practice and Future Perspectives.

Catheter ablation to perform pulmonary vein isolation (PVI) is established as a mainstay in rhythm control of atrial fibrillation (AF). The aim of this review is to provide an overview of current practice and future perspectives in AF ablation. The main clinical benefit of AF ablation is the reduction of arrhythmia-related symptoms and improvement of quality of life. Catheter ablation of AF is recommended, in general, as a second-line therapy for patients with symptomatic paroxysmal or persistent AF, who have failed or are intolerant to pharmacological therapy. In selected patients with heart failure and reduced left-ventricular fraction, catheter ablation was proven to reduce all-cause mortality. Also, optimal management of comorbidities can reduce AF recurrence after AF ablation; therefore, multimodal risk assessment and therapy are mandatory. To date, the primary ablation tool in widespread use is still single-tip catheter radiofrequency (RF) based ablation. Additionally, balloon-based pulmonary vein isolation (PVI) has gained prominence, especially due to its user-friendly nature and established safety and efficacy profile. So far, the cryoballoon (CB) is the most studied single-shot device. CB-based PVI is characterized by high efficiency, convincing success rates, and a beneficial safety profile. Recently, CB-PVI as a first-line therapy for AF was shown to be superior to pharmacological treatment in terms of efficacy and was shown to reduce progression from paroxysmal to persistent AF. In this context, CB-based PVI gains more and more importance as a first-line treatment choice. Non-thermal energy sources, namely pulsed-field ablation (PFA), have garnered attention due to their cardioselectivity. Although initially applied via a basket-like ablation tool, recent developments allow for point-by-point ablation, particularly with the advent of a novel lattice tip catheter.

Real-time interactive 3d simulation of Atrial Fibrillation for education

Abstract Background The mechanistic understanding of atrial fibrillation (AF) has burgeoned over the past decades. However, the interplay between triggers, reentry, drivers and therapies is rarely fully appreciated despite being ultimately fundamental to patient care. Readily accessible, high-fidelity interactive simulation has the potential to address this knowledge gap across healthcare providers. Objective To develop a, interactive simulation system to allow deep understanding of AF mechanisms and therapies. Methods An application for e-Training was developed to be accessible on consumer smartphones and tablets, based on a validated electromechanical simulation model of the heart, with real-time interactive 3D image output. A virtual heart is represented in normal and arrhythmic states, enabled with simulated models for administering antiarrhythmic drugs, performing Pulmonary Vein Isolation (PVI), AV Node ablation, ventricular pacing, DC Cardioversion, plus the formation of atrial thrombus leading to a stroke event. Electrogram and ECG signals are generated from the underlying simulation and respond realistically to drugs, pacing and ablation. A self-study tutorial introduces the arrhythmia and treatment procedures. Learning outcomes are assessed with MCQ tests and receive Continuous Professional Development CPD credits. Results The AFib Sim app has received CPD accreditation in the UK and has so far been used at the Universities of Oxford, Cambridge and Leeds medical schools. All trainees and medical students followed the self-study tutorials and took the interactive MCQ test, which are embedded within the AFib Sim app. Development was based on Unity 3D and was made available on iOS, Android, macOS, MS Windows and WebGL platforms. Conclusion This project meets an urgent training need whilst expanding expertise and market scope into clinical training. The impact on clinical training was high and the societal benefit came from better and quicker trained staff. Learning Objective Upon completion of this session, the attendee will be able understand how a simulation of Atrial Fibrillation can be used for training and deepening the clinical understanding of atrial fibrillation.

Usefulness of three-dimensional pulmonary vein-left atrium image reconstructed from non-enhanced computed tomography for atrial fibrillation ablation.

Enhanced computed tomography (CT) is unsuitable for patients with reduced renal function and/or allergy for contrast medium (CM). CT image registration into an electroanatomic system (EAMS) is essential to perform pulmonary vein isolation (PVI) safely and smoothly in patients with atrial fibrillation (AF). To create three-dimensional pulmonary vein-left atrium (3D PV-LA) images from non-enhanced CT images to register them into EAMS for AF ablation. Using a non-enhanced ECG-gated image, 3D PV-LA images were generated by our developed techniques with an EnSite image analyzing tool for patients unfit for CM use (n = 100). Segmentation between tissues was performed as follows: tissues distal from or close to PV-LA were segmented in transverse slices to clearly show the whole LA. Tissues bordering PV-LA, including the pulmonary artery, left ventricle, and right atrium, were segmented manually with great care. Practical ablation parameters were compared with those obtained from enhanced CT (n = 100). 3D PV-LA image reconstruction from non-enhanced CT imaging required a longer time than that from enhanced CT (42 ± 6 vs 14 ± 3 min). All 100 PV-LA non-enhanced CT images were successfully reconstructed and registered into the EAM system without the need for re-segmentation. Practical ablation parameters, including procedural time and AF recurrence rate, did not differ between imaging methods. This study provides clinically useful information on a detailed methodology for 3D PV-LA image reconstruction using non-enhanced CT. Non-enhanced CT 3D PV-LA images were successfully registered into the EAM system and useful for patients unsuitable for CM use.

Acute lesion extension following pulmonary vein isolation with two novel single shot devices: Pulsed field ablation versus multielectrode radiofrequency balloon.

Pulsed-field ablation (PFA) and the multielectrode radiofrequency balloon (RFB) are two novel ablation technologies to perform pulmonary vein isolation (PVI). It is currently unknown whether these technologies differ in lesion formation and lesion extent. We compared the acute lesion extent after PVI induced by PFA and RFB by measuring low-voltage area in high-density maps and the release of biomolecules reflecting cardiac injury. PVI was performed with a pentaspline catheter (FARAPULSE) applying PFA or with the compliant multielectrode RFB (HELIOSTAR). Before and after PVI high-density mapping with CARTO 3 was performed. In addition, blood samples were taken before transseptal puncture and after post-PVI remapping and serum concentrations of high-sensitive Troponin I were quantified by immunoassay. Sixty patients undergoing PVI by PFA (n = 28, age 69 ± 12 year, 60% males, 39.3% persistent atrial fibrillation [AF]) or RFB (n = 32, age 65 ± 13 year, 53% males, 21.9% persistent AF) were evaluated. Acute PVI was achieved in all patients in both groups. Mean number of PFA pulses was 34.2 ± 4.5 and mean number RFB applications was 8.5 ± 3 per patient. Total posterior ablation area was significantly larger in PFA (20.7 ± 7.7 cm²) than in RFB (7.1 ± 2.09 cm²; p < .001). Accordingly, posterior ablation area for each PV resulted in larger lesions after PFA versus RFB (LSPV 5.2 ± 2.7 vs. 1.9 ± 0.8 cm², LIPV 5.5 ± 2.3 vs. 1.9 ± 0.8 cm², RSPV 4.7 ± 1.9 vs. 1.6 ± 0.5 cm², RIPV 5.3 ± 2.1 vs. 1.6 ± 0.7 cm,² respectively; p < .001). In a subset of 38 patients, increase of hsTropI was higher after PFA (625 ± 138 pg/mL, n = 28) versus RFB (148 ± 36 pg/mL, n = 10; p = .049) supporting the evidence of larger lesion extent by PFA. PFA delivers larger acute lesion areas and higher troponin release upon successful PVI than multielectrode RFB-based PVI in this single-center series.

Pulsed-field ablation based pulmonary vein isolation: reconnection pattern and comparison to cryoballoon ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed-field ablation (PFA) integrated into a pentaspline catheter is a novel single shot device to perform pulmonary vein isolation (PVI) for treatment of atrial fibrillation (AF). While initial data demonstrated high safety and efficacy, long-term PVI durability and reconnection patterns are unknown. Here, we analyzed findings from repeat ablation procedures after index PFA compared to cryoballoon ablation (CBA) based PVI. Methods We prospectively included consecutive patients with index PVI applying PFA (n=161) or CBA (n=302) who underwent repeat ablation due to symptomatic recurrence of AF or atrial tachycardia (AT) after a blanking period of 3 months. All repeat procedures were performed with a 3D mapping system and RF energy. Results We identified a total of 14 patients after previous PFA and 23 patients after previous CBA. PV reconnection was detected in 9/14 (64%) patients after PFA and in 16/23 (70%) after CBA (p=1.000). A total of 24/55 (44%) vs. 34/92 (37%) initially isolated PVs demonstrated electrical reconduction (p=0.487) after PFA and CB ablation. In both groups the right inferior PV was reconnected most frequently (9/24 (38%) patients after PFA and 10/34 (29%; p=0.578) patients after CBA). Distribution of conduction gaps is shown in figure 1. All PVs were successfully reisolated. Repeat procedures after index PFA and CBA showed similar duration (115±32 min vs. 114±49 min; p=0.785), fluoroscopy time (13±4 min vs. 14±8 min; p=0.558) and number of RF applications (38±23 vs. 36±34, p=0.738). Conclusion During repeat AF/AT ablation after previous PFA- or CBA-based PVI a comparable incidence of PV reconduction gaps was found. Repeat procedure times and fluoroscopy exposure were similar. Randomized controlled trials and longer follow-up are necessary to draw further conclusions.

AB-452675-2 PULMONARY VEIN ISOLATION USING A NOVEL MAP-AND-ABLATE SPHERICAL ARRAY PULSED FIELD ABLATION CATHETER: THE PULSE-EU PAROXYSMAL AF COHORT

Despite the promise of pulsed field ablation (PFA), there is much about the biophysics of this novel energy technology that remains to be understood. Preclinical studies have shown that close electrode-tissue proximity increases the likelihood of achieving transmural PFA lesions by maximizing the electric field penetration into the target tissue. The current single-shot PFA catheters are capable of performing pulmonary vein isolation (PVI), but cannot reliably confirm tissue contact. To report the clinical outcomes using a novel Map-and-Ablate spherical array multielectrode catheter that is able to verify tissue contact and deliver single-shot PFA. In the first-in-human PULSE-EU study, paroxysmal AF pts underwent PVI using the spherical array PFA catheter (Globe; Kardium Inc., Canada) using a 16Fr deflectable sheath under general anesthesia and ICE-guidance. Using a custom mapping system integrated with the PFA catheter (GPS; Kardium Inc.) the array catheter rendered contact and voltage anatomic maps. The spherical array was positioned at each PV ostia and PF applications (1.7 kV/lesion, ungated, micro-second scale pulses) were delivered after verifying tissue contact (Figure). Follow-up included post-procedure EGD and plans for protocol-mandated invasive remapping at 2-3 mo after the index procedure. A total of 24 pts (age 59.9±10.8 years; gender women-37.5%; LA 42.5±3.7 mm; LVEF 62.6±8.0%%) underwent PVI with a total procedure duration of 71.5±22.9 min. All PVs (96 of 96 PVs) were acutely isolated, typically with a single application. There were no acute reconnections. The total pulse delivery time and LA catheter dwell time were 42.2±7.6 sec and 36.8±13.7 min, respectively. There were no serious procedure or device related adverse events including no stroke/TIA, pericardial effusion, phrenic nerve injury, or esophageal complications. One patient had pericarditis which was treated medically. Post-procedure EGD revealed no thermal injury in 21 of 21 pts. PV remapping has thus far been performed in 6 pts, and revealed durable PVI in all 24 of 24 (100%) PVs. [Remapping data on the remaining cohort will be available by May 2023.] In this first-in-human PULSE-EU clinical study, the spherical array PFA catheter was able to render atrial anatomy, isolate PVs (with initial data indicating 100% durability), and perform pre-/post- electrical mapping.

Pulmonary vein isolation by visually guided laser balloon ablation: single-center 5-year follow-up results

BackgroundVisually guided laser balloon (VGLB) ablation is a balloon-based treatment for atrial fibrillation (AF) that uses a titratable laser energy source to perform pulmonary vein isolation (PVI), allowing for real-time visualization of target tissue and ablation lesions through an endoscopic camera. Few long-term data on this technique are currently available. This report presents acute efficacy, procedural data, complication rates, and long-term AF-free survival up to 5 years post-ablation.MethodsIn this single-center, retrospective, observational report, 152 patients (72.4% male, mean age 60.6 ± 9.7 years, 62.5% paroxysmal AF, 598 pulmonary veins in total) treated with the first-generation VGLB system between 2014 and 2016 were included for analysis. AF ablation consisted of PVI only.ResultsAcute PVI was achieved in 98.2% of veins, with first-pass isolation in 92.5%. Procedure duration of 129 min [IQR 113–150], fluoroscopy time of 15 min [IQR 11–20], and dose area product of 5016 mGy·cm2 [IQR 3603–8711] were recorded. During a median follow-up of 51 months [IQR 45–57], 74.3% of patients remained free of AF (78.8% for paroxysmal and 65.3% for persistent AF, p = 0.108). Freedom of AF at 1, 2, 3, and 4 years follow-up was 88.2%, 82.2%, 78.9%, and 74.8%, respectively. PV reconnections were identified in only 46.9% of redo procedures. The median number of PV reconnections during redo procedures was 0 [IQR 0–2]. Anti-arrhythmic drug use was significantly reduced after ablation (p < 0.001). The most commonly reported complications were minor vascular complications (4.6%) and transient phrenic nerve paralysis (3.3%).ConclusionsFirst-generation VGLB ablation demonstrated high acute isolation rates, reasonable procedure times and low complication rates. Long-term freedom from AF was 78.8% for paroxysmal AF and 65.3% for persistent AF, performing PVI only.

Ablation index-guided high-power ablation for superior vena cava isolation in patients with atrial fibrillation.

The strategy of ablation index (AI)-guided high-power ablation seems to be a novel strategy for performing pulmonary vein isolation (PVI). An AI-guided high-power ablation strategy was used in this study to determine whether superior vena cava isolation (SVCI) after PVI was feasible and safe for patients with AF. Data from 53 patients with AF were collected. Mapping and ablation of SVC were performed. The applied power was set at 45 W and the procedure was guided by AI. The SVC was divided into six segments in a cranial view. The RF applications and AI values in different segments were compared and analyzed. Using receiver operating characteristic (ROC) analysis, the diagnostic accuracy of AI value for predicting segment block was evaluated. Electrical SVCIs were successfully achieved in all patients. SVCI was performed by segment ablation in most cases, with RF applications in different segments. The mean AI value in non-lateral walls was higher than that of the lateral wall (392 ± 28 vs. 371 ± 37, P < 0.001). Acutely blocked sites had significantly larger AI values compared with no-blocked sites (390 ± 30 vs. 343 ± 23, P < 0.001). The optimal AI cut-off value for non-lateral segments was 379 (sensitivity: 75.9%, specificity: 100%) and for lateral segments was 345 (sensitivity: 82.3%, specificity: 100%). The AI values were predictive of the acute conduction block of SVCI. With AI values of 345 and 379, respectively, conduction block was achieved in the lateral walls at a lower level than in the non-lateral walls.

Comparison of left atrial lesion size and troponin release of two novel single shot devices for pulmonary vein isolation: pulsed field ablation vs. multi-electrode radiofrequency balloon

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Pulsed-field ablation (PFA) and the multi-electrode radiofrequency balloon (RFB) are two novel ablation technologies to perform pulmonary vein isolation (PVI). It is currently unknown whether these technologies differ in lesion formation and lesion extent. Purpose We compared the acute lesion extent after PVI induced by PFA and RFB by measuring low-voltage area in high-density maps and the release of biomolecules reflecting cardiac injury. Methods PVI was performed with a pentaspline catheter (FARAPULSE) applying PFA or with the compliant multi-electrode radiofrequency balloon (HELIOSTAR). Before and after PVI high-density mapping with CARTO3 was performed. In addition, blood samples were taken before transseptal puncture and after post-PVI remapping. Serum concentrations of high-sensitive Troponin I (hsTropI) were quantified by Immunoassay. Results 50 patients undergoing PVI by PFA (n=26, age 71±10 y, 58% males, 58% persistent AF) or RFB (n=24; age 64±13 y, 54% males, 25% persistent AF) were evaluated. Acute PVI was achieved in all patients in both groups. Mean number of PFA pulses were n=34±5 and mean number RFB applications were n=8±3. Total posterior ablation area was bigger in PFA (19.0±6.2 cm²) than in RFB (9.0±2.2 cm²; p&amp;lt;0.001). The posterior distance between septal and lateral lesions was shorter in PFA (23.7±10.5 mm) than in RFB (30.0±7.3 mm; p=0.021). In a total of 38 patients increase of hsTropI was higher after PFA (625±138 pg/ml, n=28) vs. RFB (148±36 pg/ml; n=10; p=0.049) supporting the evidence of larger lesion extent by PFA. Conclusion Pulse-field ablation delivers larger acute lesion areas and higher troponin release upon successful pulmonary vein isolation than multi-electrode array balloon-based pulmonary vein isolation in this single-center series.

Safety of pulsed-field ablation in patients with cardiac implantable electronic devices. A single-center pilot study

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Pulsed-field ablation (PFA) is a novel energy source to perform pulmonary vein isolation (PVI) in patients with atrial fibrillation or cavo-tricuspid isthmus ablation (CTI) in patients with atrial flutter. Whether strong electrical fields generated by PFA could change the function and integrity of cardiac implantable electronic devices (CIED) is not known. Aim To assess the function and integrity of implanted devices before and after pulsed-field ablation. Methods This study included consecutive patients with CIED undergoing PFA at a large single center. Real-time CIED electrograms were recorded during PFA applications. CIED were interrogated before and after PFA assessing function (threshold, sensing), integrity (impedance), and arrhythmia episodes. Results We performed PFA in six patients (age 69±12 years, 1/6 female, left atrial diameter was 44±3 mm, left-ventricular ejection fraction 40±14%) for PVI in five patients with atrial fibrillation and CTI ablation in one patient with atrial flutter. All patients had CIEDs (one cardiac resynchronization device, two implantable cardioverter-defibrillators, three two-chamber pacemakers). Each patient undergoing PVI received 32 PFA applications of 2.5 s. (4x basket configuration and 4x flower configuration at each pulmonary vein), amounting to a total ablation time of 80 s and resulting in complete PVI in all five patients. For CTI ablation we applied 8 PFA applications of 2.5 s (20 s total ablation time) resulting in CTI blockade. Real-time intracardiac electrograms (iEGM) during PFA applications revealed sensing of single PFA application impulses in three patients and blanking of the iEGM in three patients. Postinterventional device testing revealed no changes in impedance, stimulation threshold or sensing. No leads were dislocated or damaged. No other device malfunctions occurred during the procedure, as well as no other major periprocedural complications occurred. Conclusion The function and integrity of pacemakers and defibrillators is not affected by PFA in our patient sample. Larger series are needed to confirm the apparent safety of PFA in patients with CIED.

CA-536-01 PULSED-FIELD ABLATION BASED PULMONARY VEIN ISOLATION: ACUTE SAFETY AND EFFICACY IN A MULTI-CENTER REAL WORLD SCENARIO

Pulsed-field ablation (PFA) is a new energy source to perform pulmonary vein isolation (PVI) by targeted electroporation of cardiomyocytes. Integrated into a single-shot device, PFA has the potential to increase efficacy and safety of PVI compared to thermal energy sources. To assess feasibility, efficacy and safety of PFA for index PVI in a multi-center real world setting. Consecutive patients with symptomatic paroxysmal or persistent atrial fibrillation (AF) underwent PVI using the PFA ablation catheter (Farawave®, Farapulse Inc, Menlo Park, CA, USA) at two high-volume ablation centers. The left atrium was accessed by a single transseptal puncture and PVs were located by selective PV angiographies. 3D voltage mapping of the left atrium was performed before and after PVI. A total of 110 patients (mean age 67±12 years, 62% male, 61% persistent AF) were included. PVI was achieved in all patients by deploying 3567 applications in 435 PVs (8.4±3.1 per vein). Disappearance of PV signals after the first of eight applications was demonstrated in 433/435 PVs (99%). More than eight PFA applications were applied in 23/435 PVs (0.5%) due to difficulties in positioning (3x left superior PV, 7x right superior PV, 7x right inferior PV) or due to reconnection after remapping (2x LIPV, 3x RSPV, 1x RIPV). Mean procedure time was 81±23 minutes including pre- and post PVI high-density voltage mapping. PF catheter left atrial dwell-time was 27±10 min. Left atrial dwell-time reduced from 40 to 24 min during the first 50 procedures at UHZ. Total fluoroscopy time was 16.6±9.2 minutes with a dose area product of 749±79 cGy*cm2. One pericardial tamponade occurred independent of PFA applications and two minor groin complications. No other complications occurred, especially no phrenic nerve palsy, stroke, hemoptysis, atrio-oesophageal fistula or acute symptomatic PV stenosis. In this multi-center real world setting, pulsed field ablation achieves effective pulmonary vein isolation with low complication rates.

Innovations in atrial fibrillation ablation.

Catheter-based ablation to perform pulmonary vein isolation (PVI) has established itself as a mainstay in the rhythm control strategy of atrial fibrillation. This review article aims to provide an overview of recent advances in atrial fibrillation ablation technology. We reviewed the available literature and clinical trials of innovations in atrial fibrillation ablation technologies including ablation catheter designs, alternative energy sources, esophageal protection methods, electroanatomical mapping, and novel ablation targets. Innovative radiofrequency (RF) catheter designs maximize energy delivery while avoiding overheating associated with conventional catheters. Single-shot balloon catheters in the form of cryoballoons, radiofrequency, and laser balloons have proven effective at producing pulmonary vein isolation and improving procedural efficiency and reproducibility. Pulsed field ablation (PFA) is a highly anticipated novel nonthermal energy source under development, which demonstrates selective ablation of the myocardium, producing durable lesions while also minimizing collateral damage. Innovative devices for esophageal protection including esophageal deviation and cooling devices have been developed to reduce esophageal complications. Improved electroanatomical mapping systems are being developed to help identify additional non-pulmonary triggers, which may benefit from ablation, especially with persistent atrial fibrillation. Lastly, the vein of Marshall alcohol ablation has been recently studied as an adjunct therapy for improving outcomes with catheter ablation for persistent atrial fibrillation. Numerous advances have been made in the field of atrial fibrillation ablation in the past decade. While further long-term data is still needed for these novel technologies, they show potential to improve procedural efficacy and safety.

Esophageal temperature during atrial fibrillation ablation poorly predicts esophageal injury: An observational study.

BackgroundEsophageal injury (EI) remains a concern when performing pulmonary vein isolation (PVI) using the high-power short-duration (HPSD) technique.ObjectiveWe aim to indicate that high esophageal temperature during HPSD PVI does not correlate with positive esophageal endoscopy (EGD) findings.MethodsA retrospective observational study was performed on 43 patients undergoing PVI using HPSD (50 W for 6–7 seconds per lesion) at Tulane Medical Center from July 2020 to January 2021. Esophageal temperature was monitored throughout the procedure using a temperature probe and patients underwent EGD the following day. Small ulcers, nonbleeding erosions, erythema, and/or esophagitis were considered positive EGD findings.ResultsMean age was 64.9 years; 46.5% of the patients were female. Eleven patients had positive EGD findings (group 1) and 32 patients had normal EGD (group 2). There was no statistical difference in mean esophageal peak temperature between group 1 and group 2 (43.9°C ± 2.9°C and 42.5°C ± 2.3°C, respectively, P = .17). There was no association between positive EGD results and esophageal temperature during PVI. Mean baseline esophageal temperature was similar in both groups (36.1°C, P = .78). Average contact force (P = .53), ablation time (P = .67), age (P = .3096), sex (P = .4), body mass index (P = .14), and other comorbidities did not correlate with positive endoscopy results. We found positive correlation between the distance of the left atrium (LA) to esophagus and positive EGD (P = .0001).ConclusionEI during HPSD PVI does not correlate to esophageal temperature changes during ablation. However, esophageal injury does correlate to a shorter proximity of the esophagus to the LA.

Third-generation laser balloon ablation for atrial fibrillation treatment: a multicenter experience

Abstract Background Laser balloon ablation is a promising option for performing pulmonary vein isolation (PVI) which is the cornerstone of invasive atrial fibrillation (AF) treatment. Purpose We aimed to investigate the acute efficacy and safety of the novel third-generation of the laser balloon system in an initial multicenter experience. Methods First and consecutive patients who underwent PVI with LB3 for drug-resistant paroxysmal or persistent AF at 7 Italian sites were included in this analysis. Study endpoints were acute procedural efficacy, defined as successful isolation of all identified PVs without radiofrequency touch-up, total and fluoroscopy times, and periprocedural complications. Results Our population included 86 patients (81% males, mean age 60.6±9.5 years) who underwent a procedure of PVI using LB3 between June 2020 and March 2021. Most patients had paroxysmal AF (74%) and were in sinus rhythm at the beginning of the procedure. The mean procedure time was 138±60 min; fluoroscopy time was 22±17 min and the mean ablation time was 44±40 min. Of the 313 targeted PVs, 311 (99.4%) could be isolated with first-pass LB3 application, while 2 (0.6%) required radiofrequency touchup. At the end of the procedure, all patients were in sinus rhythm and 26 (32%) received electrical cardioversion to achieve stable sinus rhythm. The total rate of major compilations was 1.2% (1/82 patients): one pericardial tamponade requiring epicardial puncture. No surgical intervention was necessary, and the patient recovered without any sequalae. There were no vascular access complications or phrenic nervy palsy. Three pinhole balloon raptures (3.5%) were observed during energy applications that required replacement of the whole system but had no effect on patient safety. Conclusions In a first multicenter experience, the LB3 system for PVI was safe with excellent acute efficacy. Funding Acknowledgement Type of funding sources: None.

Characterization of atrial lesion safety and efficacy utilizing a circular catheter and the IRE generator with an in vivo porcine model

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): Biosense Webster, Inc. Introduction/Objectives: Pulsed field ablation (PFA) is a non-thermal ablative method that delivers high voltage, very-short duration pulses that cause pore formation in the cytoplasmic membrane and cell death. The tissue selectivity of PFA is expected to reduce the risk of collateral tissue injury compared to radiofrequency catheter ablation (RFCA), while maintaining effectiveness. The objective of this study was to perform pulmonary vein (PV) isolation in a porcine model to characterize the safety and performance of a novel, fully-integrated biphasic PFA system. The system is comprised of a multi-channel generator, a variable loop circular catheter, and an integrated irreversible electroporation (IRE) mapping software module. Methods The study evaluated safety and efficacy of IRE in 8 healthy swine. First, to evaluate safety, multiple ablations were performed at various cardiac structures, including within the lumen of the right pulmonary vein (RIPV), at the right superior pulmonary vein (RSPV) ostium, and adjacent to the esophagus. Second, to evaluate efficacy, animals were recovered and followed for 30 (±3) days, then re-mapped. Gross pathological and histopathological examinations were performed to assess for procedural injury, chronic thrombosis, tissue ablation, depth of penetration, healing, and level of inflammatory response. Results All 8 swine survived for the 30 (±3) day follow up (FU) period. There were no acute (day of procedure) incidents of pulmonary vein narrowing of &amp;gt;70%, nor at 30 d follow-up (FU), even when ablation was purposefully performed directly deep to the ostium of the vein. No injury was seen grossly or histologically in the adjacent esophagus. All PVs were durably isolated as confirmed by bidirectional block at the 30 (±3) day re-map procedure, and histological examination showed complete, transmural necrosis around the entire circumference of the ablated section of the right PVs [Figure]. Conclusion(s): This pre-clinical evaluation of a fully integrated PFA system demonstrated effective and durable ablation of cardiac tissue and PV isolation with no collateral damage to adjacent structures. Notably, histological staining confirmed complete transmural cell necrosis around the circumference of the ostial PV at 30 days. Abstract Figure. PVI maps (A) histology (B) and safety(C)

Long-term durability of posterior wall isolation using the cryoballoon in patients with persistent atrial fibrillation: a multicenter analysis of repeat catheter ablations

There is a growing interest in performing pulmonary vein isolation (PVI) with concomitant posterior wall isolation (PWI) using the cryoballoon for the treatment of patients with persistent atrial fibrillation (AF). However, there is little known about the long-term durability of PWI using this approach. In this multicenter study, we retrospectively examined the durability of PVI + PWI using the 28-mm cryoballoon by investigating the outcomes from consecutive patients referred for repeat catheter ablation. Altogether, 81/519 patients (15.6%) were referred for repeat catheter ablation. Repeat ablation was associated with a longer AF duration, hypertension, heart failure, multiple cardioversions, and antiarrhythmic therapy as well as larger left atrial (LA) diameters (49 ± 4 mm versus 43 ± 5 mm; P < 0.001) and greater need for "touch-up" (adjunct) radiofrequency ablation (44.4% versus 18.3%; P < 0.001). LA diameter also emerged as a significant predictor for adjunct radiofrequency ablation (P < 0.001). Durable PVI was observed in 66/81 patients (81.5%) and PWI in 67/81 patients (82.7%). Those with incomplete PWI exhibited larger LA diameters, particularly > 48 mm (negative predictive value = 89.7%). Lastly, an atypical LA posterior wall/roof flutter represented the third most common cause of arrhythmia recurrence and essentiallyevery patient with incomplete PWI exhibited such an arrhythmia. PWI performed using a 28-mm cryoballoon in conjunction with PVI exhibits long-term durability in the vast majority of patients with persistent AF. While LA diameter (particularly > 48 mm) is a significant predictor for the need for adjunct radiofrequency ablation when performing this technique, those with incomplete PWI invariably present with an atypical flutter using this substrate.