Pulsed-field ablation does not induce esophageal and periesophageal injury-A new esophageal safety paradigm in catheter ablation of atrial fibrillation

Current Safety Profile of Pulse Field Ablation: Not Everything that Shines Is Gold

Pulse field ablation is a novel, non-thermal alternative for catheter ablation of atrial fibrillation. Preclinical and early clinical studies have demonstrated a favorable safety profile with significant reductions in esophageal and pulmonary vein injury compared to radiofrequency ablation. However, there are still procedural and energy-related complications inherent to electroporation, tissue selectivity, and energy-dosing. Minimizing the frequency of application and extent of energy, as well as careful selection of the energy source, may mitigate these adverse events. There remains controversy and a lack of long-term outcomes, highlighting the need for further evaluation.

Outcomes of Exclusive 50 W High Power, 5 s Ablation Close to the Esophagus in Pulmonary Vein Isolation

BACKGROUND

In pulmonary vein isolation (PVI) employing a high-power and short-duration (HP-SD) strategy, no consensus exists regarding the optimal settings for radiofrequency application (RFA) to the section of left atrium adjacent to the esophagus (esophageal area, EA).

OBJECTIVE

To evaluate (1) the efficacy and safety of HP-SD RFA with 50 W for 5 s on the EA, and (2) the predictive factors of esophageal thermal injury (ETI).

METHODS

We performed esophagogastroduodenoscopy on 85 patients who had undergone PVI with 50 W RFA. RFA duration was limited to 5 s on the EA.

RESULTS

Of the 85 patients, 16 (18.8%) developed asymptomatic thermal injury (1 mucosal injury, namely erosion and 15 gastric hypomotility). All of those were asymptomatic and transient, and any symptomatic or severe, esophageal or gastric complications was not observed. On the EA, conduction block was achieved after the first encircling in 82 (96.5%) patients. The number of RFA on the EA and the proportion of patients whose EA was located at the posterior wall of the right inferior PV (right-sided EA) were higher in the patients with ETI than without (9.0 [7.0-10.5] vs. 7.0 [5.0-9.0] p = 0.021, and 18.8% vs. 2.9%, p = 0.044, respectively). In multivariate analysis, the number of RFA on the EA (hazard ratio 1.32, p = 0.019) and RFA on the right-sided EA (hazard ratio, 13.50, p = 0.013) were identified as the predictors of ETI.

CONCLUSION

RFA of 50 W for 5 s on the EA can be performed with a low incidence of esophageal mucosal injury while maintaining efficacy. RFA on the right-sided EA and the high number of RFA on the EA increase the risk of ETI.

Pulsed-field ablation versus radiofrequency or cryoballoon thermal ablation in atrial fibrillation: a systematic review and meta-analysis

This review investigated efficacy and safety of pulsed-field ablation (PFA) in comparison with radiofrequency ablation (RFA), cryoballoon ablation (CBA), or both combined. The Odds ratio (OR) and mean difference (MD) with 95% confidence interval (95% CI) were computed. PFA allowed shorter procedure (MD -44.27 minutes, 95% CI: -63.61; -24.93) and left atrium (LA) dwell (MD -32.71 minutes (95% CI: -58.64; -6.78) times, but with longer fluoroscopy time than RFA (MD 8.54 minutes, 95% CI: 4.03; 13.04). Post-procedural complications rate was lower with PFA than CBA (OR 0.53, 95% CI: 0.35, 0.80). Atrial arrhythmias recurrence rate within one year of follow-up was lower with PFA than RFA (OR 0.68, 95% CI; 0.53; 0.87) and CBA (OR 0.69, 95% CI: 0.48; 0.97). PFA allowed shorter procedure and LA dwell times, as well as lower atrial arrhythmia recurrence than RFA and lower post-procedural complications and atrial arrhythmias recurrence rates than CBA.

Thermal and Non-Thermal Energies for Atrial Fibrillation Ablation

The cornerstone of ablative therapy for atrial fibrillation (AF) is pulmonary vein isolation (PVI). Whether PVI should be added with additional lesions in persistent atrial fibrillation (PerAF) or for any post-ablative recurrent AF is a matter of debate. Whatever the ablative strategy, it must determine the choice of energy source to achieve the most durable lesion sets with the least likelihood of complications. Radiofrequency (RF) is the most studied thermal ablation technique. It can be combined with high-density electroanatomic mapping and can be used for both pulmonary and extrapulmonary atrial ablation. Cryoenergy is at least as effective as radiofrequency for PVI; it is rapid, relatively safe, and has a steep learning curve. Therefore, it has been proposed as a first-line approach for PVI-only procedures. More recently, a non-thermal technique based on the application of pulsed direct current (Pulsed Field Ablation-PFA) has been introduced. PFA causes cell death by opening cell membrane pores (electroporation) without a significant increase in tissue temperature. It is fast and does not alter the extracellular matrix as thermal techniques do, although it ends up causing long-lasting, transmural lesions. Most importantly, it is relatively selective on cardiac myocytes and therefore potentially safer than thermal techniques. Some PFA systems can be combined with electroanatomic mapping systems. However, as of now, it appears that these ablation technologies should be considered complementary rather than alternative for a number of practical and theoretical reasons.

Feasibility and Clinical Efficacy of Focal Pulsed Field Ablation in Patients With Non-Pulmonary Vein Triggered Atrial Arrhythmia From the Superior Caval Vein

INTRODUCTION

In patients with atrial arrhythmias originating from the superior vena cava (SVC), the use of radiofrequency energy to isolate the SVC is associated with a significant risk of injury both to the phrenic nerve and the sinus node. Pulsed field ablation (PFA) may overcome the disadvantages of thermal energy and improve both ablation efficacy and safety.

OBJECTIVE

We report the feasibility, safety, and clinical efficacy of focal monopolar PFA in patients with the origin of their atrial arrhythmia in the SVC.

METHODS

Nine patients (7 men, age 66 ± 8 years) with SVC-induced paroxysmal AF (n = 3), persistent AF (n = 5), or frequent premature atrial beats (n = 1) underwent SVC isolation using focal monopolar PFA.

RESULTS

Acute circumferential SVC isolation was achieved in all cases, using 22 Ampere (A) or 25 A in areas with or without phrenic capture, respectively. The safety profile was excellent: two patients had transient sinus arrest and two had transient phrenic nerve stunning. Sinus node and phrenic nerve function recovered during the procedure, and no permanent damage was observed at follow-up. Coronary vasospasm occurred (and quickly resolved after injection of nitroglycerin) in one patient during additional ablation of a focal atrial tachycardia at the coronary sinus ostium. Kidney function remained stable before and after ablation in all patients.

CONCLUSIONS

In this patient cohort with SVC-triggered atrial arrhythmia, isolation using focal monopolar PFA was feasible, effective, and safe. No permanent injury to the phrenic nerve or sinus node was observed.

Effectiveness and Safety of Pulsed Field Ablation in Patients With Atrial Fibrillation

BACKGROUND

As a competitive nonthermal energy technique used in atrial fibrillation (AF), the effectiveness and safety of pulsed field ablation (PFA) has remained uncertain.

OBJECTIVES

The authors meta-analysis aimed to investigate the effectiveness and safety of PFA in treating AF patients and compare its outcomes with conventional thermal ablation.

METHODS

The PubMed, Embase, and Cochrane Library databases were systematically searched until January 2024 for relevant studies investigating the use of PFA for AF. A fixed-effects model was used for pooled analysis if the I2 value was <50%; otherwise, a random-effects model was applied.

RESULTS

A total of 46 studies were included in this analysis. The single-arm meta-analysis of 40 studies showed an acute pulmonary vein isolation (PVI) rate of 99.79% per pulmonary vein (PV) and 99.47% per patient, with atrial arrhythmia recurrence rates of 12.36%, 12.42%, and 23.28% at 3, 6, and 12 months, respectively. The safety outcomes incidence was low. In the comparison of 21 studies between PFA and thermal ablation, PFA demonstrated comparable acute PVI rates but a higher first-pass isolation rate. PFA was associated with a lower incidence of atrial arrhythmia recurrence after 3 months and phrenic nerve paralysis or injury, but a higher risk of cardiac perforation or tamponade. Procedure time was shorter with PFA.

CONCLUSIONS

PFA showed noninferiority to thermal ablation in acute PVI and superiority in first-pass isolation, atrial arrhythmia recurrence, phrenic nerve paralysis or injury, and procedure time. However, PFA treatment exhibited a higher risk of cardiac perforation or tamponade.

Complications associated with pulsed field ablation vs radiofrequency catheter ablation of atrial fibrillation

BACKGROUND

The first commercial systems for pulsed field ablation (PFA) were recently approved by the Food and Drug Administration, but their safety profile in nationwide practice remains underexplored.

OBJECTIVES

This study aimed to describe reported adverse events with PFA systems after their market release and to compare the relative proportion of complications associated with PFA vs radiofrequency (RF) ablation catheters.

METHODS

We conducted a search of the Manufacturer and User Facility Device Experience database for adverse event reports involving Food and Drug Administration-approved PFA and RF catheters from January 1, 2024, to July 31, 2024.

RESULTS

A total of 1237 reports detailing clinical complications (n=156 for PFA and n=315 for RF) or catheter malfunctions (n=336 for PFA and n=430 for RF) were analyzed. The most common adverse events reported for PFA were pericardial effusion, vasovagal response, and hemolysis, compared with pericardial effusion, ischemic stroke, and esophageal damage for RF ablation. The proportion of reported adverse events that were deaths was lower with PFA than with RF (2.6% vs 8.9%; P=.010). Hemolysis (9.0% vs 0%), coronary events (5.8% vs 0.6%), and vasovagal responses (14.1% vs 0%) were reported more frequently after PFA (P<.001 for all). In contrast, esophageal damage (0% vs 4.1%; P<.001) and pulmonary vein stenosis (0% vs 1.9%; P=.184) were not reported with PFA, but only with RF. Regarding catheter malfunctions, mechanical problems were reported in higher proportion after PFA than after RF (87.2% vs 17.2%; P<.001).

CONCLUSION

The reported complications associated with PFA and RF ablation differ significantly. Close attention to PFA-specific complications is essential for ensuring the safe use of PFA and for mitigating risk.

Safety and Efficacy of Pulse Field Ablation in the Treatment of Atrial Fibrillation and Its Comparison with Traditional Thermal Ablation: A Systematic Review and Meta-Analysis

BACKGROUND

The purpose of this meta-analysis was to evaluate the efficacy and safety of pulsed field ablation (PFA) and to compare it with the efficacy and safety of traditional thermal ablation in patients with atrial fibrillation (AF).

METHODS

PubMed, Web of Science, and Embase were searched for randomized or observational studies exploring the efficacy and safety of PFA and comparing PFA with traditional thermal ablation in patients with AF.

RESULTS

A total of 4437 patients from 16 studies that only included PFA as the ablation method and 1792 patients from 9 comparing PFA to traditional thermal ablation were included in the final analysis. In studies that considered PFA alone, the freedom from atrial arrhythmia recurrence was 0.80 (95% confidence interval [CI] 0.76-0.84), and the incidence of periprocedural complications was 0.03 (95% CI 0.02-0.05). In comparative studies, there was no significant difference in the freedom from atrial arrhythmia recurrence (odds ratio (OR) 1.24, 95% CI 0.90-1.72) and the incidence of periprocedural complications (OR 0.74, 95% CI 0.37-1.48) of PFA compared to that of traditional thermal ablation. In the subgroup with a follow-up period less than 12 months, PFA had higher freedom from atrial arrhythmia recurrence rate compared to thermal ablation (OR 2.19, 95% CI 1.14-4.20).

CONCLUSIONS

PFA is a safe and effective catheter ablation method that is not inferior to the traditional and well-established thermal ablation. It can be used as a treatment of choice for patients with AF.

THE PROSPERO REGISTRATION

CRD42023473026, https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=473026.

Considerations regarding safety with pulsed field ablation for atrial fibrillation

The introduction of pulsed field ablation (PFA) in electrophysiology marks a significant advancement, promising efficacy comparable to thermal ablation methods while potentially providing safety advantages. Despite a generally favorable safety profile in human trials and postmarket registries, cautious evaluation of PFA's safety is essential. This review provides a comprehensive overview of key safety considerations as we discuss a myriad of considerations ranging from thermal effects, gaseous microbubble formation, muscle contractions, and proarrhythmia to procedural techniques. We explore specific safety concerns with phrenic nerve injury, cerebral lesions, coronary artery spasm, hemolysis and pulmonary bleeding. Vigilance in safety monitoring, coupled with advancements in procedural techniques and understanding of PFA's unique effects, is crucial for optimizing the safe and effective use of PFA.

Pulsed-field ablation versus thermal ablation for atrial fibrillation: A meta-analysis

Background

Pulsed-field ablation (PFA) is an alternative to thermal ablation (TA) in patients with atrial fibrillation (AF) receiving catheter-based therapy for pulmonary vein isolation (PVI). However, its efficacy and safety have yet to be fully elucidated.

Objective

The purpose of this study was to compare the acute and long-term efficacies and safety of PFA and TA.

Methods

We performed a systematic review and meta-analysis of randomized and nonrandomized controlled trials comparing PFA and TA in patients with AF undergoing their first PVI ablation. The TA group was divided into cryoballoon (CB) and radiofrequency subgroups. AF patients were divided into paroxysmal atrial fibrillation (PAF) and persistent atrial fibrillation (PersAF) subgroups for further analysis.

Results

Eighteen studies involving 4998 patients (35.2% PFA) were included. Overall, PFA was associated with a shorter procedure time (mean difference [MD] -21.68; 95% confidence interval [CI] -32.81 to -10.54) but longer fluoroscopy time (MD 4.53; 95% CI 2.18-6.88) than TA. Regarding safety, lower (peri-)esophageal injury rates (odds ratio [OR] 0.17; 95% CI 0.06-0.46) and higher tamponade rates (OR 2.98; 95% CI 1.27-7.00) were observed after PFA. In efficacy assessment, PFA was associated with a better first-pass isolation rate (OR 6.82; 95% CI 1.37-34.01) and a lower treatment failure rate (OR 0.83; 95% CI 0.70-0.98). Subgroup analysis showed no differences in PersAF and PAF. CB was related to higher (peri)esophageal injury, and lower PVI acute success and procedural time.

Conclusion

Compared to TA, PFA showed better results with regard to acute and long-term efficacy but significant differences in safety, with lower (peri)esophageal injury rates but higher tamponade rates in procedural data.

Meta-analysis of pulsed-field ablation versus cryoablation for atrial fibrillation

PURPOSE

The available data on the treatment strategy of pulsed field ablation (PFA) for patients with atrial fibrillation (AF) is limited. This study aims to provide a comparative analysis of the efficacy, safety, and procedural efficiency between PFA and cryoballoon ablation (CBA) for AF.

METHODS

We conducted a comprehensive search of the EMBASE, PubMed, Cochrane Library, and ClinicalTrials.gov databases to identify trials comparing PFA with CBA for AF from their inception until December 2023. The odds ratio (OR) and mean difference (MD), along with a 95% confidence interval (CI), were utilized as measures of treatment effect.

RESULTS

The analysis included 15 eligible trials with a total enrollment of 1880 patients. No significant differences were found in recurrent atrial arrhythmia (OR 0.83, 95% CI 0.64, 1.07) or periprocedural complications (OR 0.78, 95% CI 0.46, 1.30) between the two ablation techniques examined in this study. However, the PFA technique demonstrated a significantly shorter procedure time (MD -7.17, 95% CI -13.60, -0.73), but a longer fluoroscopy time (MD 2.53, 95% CI 0.87, 4.19). Similarly, PFA was found to be significantly associated with a decreased incidence of phrenic nerve palsy (OR 0.20, 95% CI 0.07, 0.59), but an increased incidence of cardiac tamponade (OR 4.07, 95% CI 1.15, 14.39). Moreover, there was a significantly higher release of troponin with PFA compared to CBA (MD 470.28, 95% CI 18.89, 921.67), while the increase in S100 protein and heart rate was significantly lower with PFA than with CBA (MD -64.41, 95% CI -105.46, -17.36), (MD -8.76, 95% CI -15.12, -2.40).

CONCLUSION

The utilization of PFA provides a safer, time-saving, and tissue-specific procedure compared to CBA, while maintaining comparable success rates. This has the potential to enhance procedural efficiency and optimize resource utilization in clinical practice. These findings underscore the feasibility and promise of PFA as an alternative technique for PVI in patients with AF.

Efficacy and safety of pulsed field ablation compared to cryoballoon ablation in the treatment of atrial fibrillation: a meta-analysis

Aims

Pulmonary vein isolation (PVI) represents the gold standard in the treatment of atrial fibrillation (AF) and the use of single-shot techniques, such as cryoballoon ablation (CBA) and pulsed field ablation (PFA) using a pentaspline catheter, has gained prominence. Recent studies hypothesize that PFA might be superior to CBA, although procedural efficacy and safety data are inconsistent. A meta-analysis was conducted to compare both energy sources for the treatment of AF.

Methods and results

A structured systematic database search and meta-analysis were performed on studies investigating outcomes, periprocedural complications, and/or procedural parameters of AF patients treated by either CBA or PFA. Eleven studies reporting data from 3805 patients were included. Pulmonary vein isolation by PFA was associated with a significantly lower recurrence of atrial fibrillation/atrial tachycardia [odds ratio (OR) = 0.73, 95% confidence interval (CI) = 0.54-0.98, I2 = 20%] and fewer periprocedural complications (OR = 0.62, 95% CI = 0.40-0.96, I2 = 6%) compared to CBA. The lower complication rate following PFA was mainly driven by fewer phrenic nerve injuries (OR = 0.19, 95% CI = 0.08-0.43, I2 = 0%). However, there were more cases of cardiac tamponades after PFA (OR = 2.56, 95% CI = 1.01-6.49, I2 = 0%). Additionally, using PFA for PVI was associated with shorter total procedure times [mean difference (MD) = -9.68, 95% CI = -14.92 to -4.43 min, I2 = 92%] and lower radiation exposure (MD = -148.07, 95% CI = -276.50 to -19.64 µGy·mI2 = 7%).

Conclusion

Our results suggest that PFA for PVI, compared to CBA, enables shorter procedure times with lower arrhythmia recurrence and a reduced risk of periprocedural complications. Randomized controlled trials need to confirm our findings.