Myocardial injury and inflammation following pulsed-field ablation and very high-power short-duration ablation for atrial fibrillation

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.

Pulsed Field Versus High-Power Short-Duration Radiofrequency Ablation in Atrial Fibrillation: A Meta-Analysis

BACKGROUND

Atrial fibrillation, which has increased in prevalence by 33% over the past two decades, affects 59 million people worldwide. It is treated using thermal and nonthermal techniques like radiofrequency, cryoballoon, laser, and pulsed-field ablation (PFA). This meta-analysis is the first to compare PFA with high-power short-duration radiofrequency ablation (HPSD-RFA).

METHODS

We comprehensively searched PubMed, Cochrane Central, and ScienceDirect from inception to August 2024. In Review Manager 5.4.1, we pooled risk ratios (RRs) and weighted mean difference (WMD) along with 95% confidence intervals for dichotomous and continuous outcomes, respectively, and employed a random effects model. Study quality was assessed via the Newcastle-Ottawa Scale, and funnel plots were used to evaluate the risk of publication bias.

RESULTS

Seven studies with a total of 1538 patients were analyzed in this meta-analysis. PFA was associated with a shorter total procedural time (MD = -36.39 min; 95% CI: [-46.23, -26.55]; p < 0.00001; I2 = 90%), left atrial dwell time (MD = -33.22 min; 95% CI: [-53.21, -13.23]; p = 0.001; I2 = 93%), and a longer fluoroscopy time compared to the HPSD-RFA (MD = 9.06 min; 95% CI: [6.13, 11.99]; p < 0.00001; I2 = 96%). Other outcomes were comparable between the two arms.

CONCLUSION

PFA outperforms HPSD ablation in terms of procedural efficiency outcomes except for the total fluoroscopy time. Still, both techniques are comparable regarding safety and arrhythmia control outcomes.

Clinical impact of very high-power-short-duration catheters on biomarkers after atrial fibrillation ablation

Background

Very high-power short-duration (vHPSD) catheters are associated with less irrigation fluid load than standard (STD RF) ablation catheters. However, the impact of this fluid reduction on biomarkers in pulmonary vein isolation (PVI) for atrial fibrillation (AF) remains unknown.

Methods and Aim

Biomarkers of heart failure, myocardial injury, and systemic inflammation status as Brain Natriuretic Peptide (BNP), high-sensitivity Troponin I (hsTnI), and C-reactive protein (CRP) were collected pre- and post-procedure of PVI for symptomatic AF. The study aimed to assess the impact of vHPSD catheter compared to an STD catheter (respectively irrigation of 8 vs. 15 mL/min during ablation) on biomarker alterations.

Results

The study included 83 consecutive patients (59 males [71.1%], mean age 62.6 ± 11 years), with vHPSD catheters used in 53 cases (63.9%). No significant baseline differences were observed between groups.Fluid irrigation resulted in significantly lower with vHPSD catheter than STD RF (434.8 ± 105.6 vs. 806.6 ± 256.5 mL, p < .001). Correspondingly, BNP variation was significantly lower in the vHPSD group than in the STD RF group, both in absolute change (12 [IQR -9-47] pg/mL vs. 44.5 [IQR 21-88.7] pg/mL, p = .002) and percentage change (16.3 [IQR -13.2-108.6] % vs. 84.1 [IQR 32.5-172.1] %, p = .012). When considering absolute values, a statistically significant increase in BNP was found only in the STD catheter group (from 52 [IQR 35.2-113.5] to 113 [IQR 66.7-189.5] pg/mL, p < .001), whereas no significant increase was observed in the vHPSD group (p = .06). CRP levels increased post-PVI in both groups, but the delta was significantly lower in the vHPSD group (p = .025). No significant differences in post-procedural hsTnI were detected between groups.

Conclusion

The use of a vHPSD catheter is associated with reduced fluid irrigation and a correspondingly smaller increase in BNP, a biomarker indicative of fluid overload and heart failure.

Meta-Analysis of Pulsed-Field Ablation Versus- High-Power Short-Duration Ablation for Atrial Fibrillation

PURPOSE

To optimize the effectiveness and safety of pulmonary vein isolation, pulsed-field ablation (PFA) and high-power short-duration ablation (HPSD) have recently been incorporated into clinical practice. The objective of this study is to conduct a comparative analysis, focusing on the efficacy, safety, and procedural efficiency of PFA and HPSD in the treatment of atrial fibrillation (AF).

METHODS

A thorough search was performed across multiple databases to identify trials that compared PFA with HPSD for AF from their inception until July 2024. The odds ratio (OR) and mean difference (MD), accompanied by a 95% confidence interval (CI), were employed as indicators of treatment efficacy.

RESULTS

The analysis included six eligible trials, encompassing a total enrollment of 1382 patients. No statistically significant disparities were observed in terms of freedom from any atrial arrhythmia (OR 1.10; 95% CI 0.75, 1.63) or periprocedural complications (OR 1.04; 95% CI 0.52, 2.09) between the two ablation techniques. The likelihood of requiring a repeat ablation procedure was significantly reduced with PFA compared to HPSD (OR 0.63; 95% CI 0.41-0.97); however, there was no significant difference in the incidence of PV reconnection between patients initially treated with HPSD and those using PFA (OR 0.83; 95% CI 0.53-1.30). The PFA technique demonstrated significantly shorter procedure time (MD -34.58; 95% CI -45.20, -23.96) and left atrium (LA) dwell time (MD -34.52; 95% CI -58.42, -10.61), but longer fluoroscopy time (MD 8.81; 95% CI 6.25, 11.37). The subgroup analyses revealed that PFA continued to exhibit superior procedure time and LA dwell time but inferior fluoroscopy time.

CONCLUSION

The efficacy and safety profiles of both PFA and HPSD are comparable in patients undergoing ablation therapy for AF; however, PFA is associated with shorter procedural time and longer fluoroscopy time.

Signaling Pathways (TNF-α-NF-κB, TLR2-TLR4 as well as ROS-MDA) and Cardiac Damages during Cardiac Surgeries (Coronary Stenting, Permanent Pacemaker Implantations, Radiofrequency Ablations)

INTRODUCTION

The mutual activations of multiple signaling pathways are the key factors in the development and progression of myocardial cell injuries.

OBJECTIVES

This research aimed to compare the different degrees of myocardial injury after coronary stenting, permanent pacemaker implantations, or cardiac radiofrequency ablation and to investigate the effects of the mutual activation of TNF-α/NF-κB, TLR2/TLR4, and ROS/MDA signaling pathways on myocardial injury in elderly patients after coronary stents or permanent pacemakers or radiofrequency ablation.

METHODS

We determined reactive oxygen species (ROS), malondialdehyde (MDA), toll-like receptor 2 (TLR2), toll-like receptor 4 (TLR4), nuclear factor kappa B (NF-κB), tumor necrosis factor- α (TNF-α) and high-sensitive cardiac troponin T (hs-cTnT) as markers of myocardial injury in patients.

RESULTS

The levels of ROS, MDA, TLR2, TLR4, NF-κB, TNF-α, and hs-cTnT were increased in patients with permanent pacemaker implantations when compared to patients with cardiac radiofrequency ablation (P < 0.01) at 6 months and were further increased in patients with coronary stenting compared to patients with cardiac radiofrequency ablation and permanent pacemaker implantations at 6 months, respectively (P < 0.01). This research confirmed that ROS, MDA, TLR2, TLR4, NF-κB, and TNF-α predicted myocardial injury severity.

CONCLUSION

Oxidative stress (ROS/MDA signaling pathway) may be linked to immune response (TLR2/TLR4 signaling pathway) and pro-inflammatory response (TNF-α/NF-κB signaling pathway) in myocardial injury, and ROS/MDA signaling may play a dominant role.

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.

Pulsed Field Ablation of Paroxysmal Supraventricular Tachycardia: A Prospective Multicenter Single-Arm Study in China

BACKGROUND

Pulsed field ablation (PFA) has gained attention in cardiac electrophysiology, but data on its application to paroxysmal supraventricular tachycardia are limited. This study aimed to assess the feasibility and safety of PFA and its combination with radiofrequency ablation for treating paroxysmal supraventricular tachycardia.

METHODS

A prospective, multicenter, single-arm study was conducted across 8 centers in China. Patients with atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia, or Wolff-Parkinson-White syndrome underwent ablation using a focal point dual-mode PFA/radiofrequency ablation catheter. PFA was used to achieve acute ablation success, with consolidation using PFA for atrioventricular nodal reentrant tachycardia or near-His accessory pathways and radiofrequency ablation for far-His accessory pathways. Primary and secondary end points were acute ablation success and 180-day follow-up success, respectively.

RESULTS

A total of 158 patients (77 with atrioventricular nodal reentrant tachycardia, 63 with atrioventricular reentrant tachycardia, 16 with Wolff-Parkinson-White, and 2 with both atrioventricular nodal reentrant tachycardia and atrioventricular reentrant tachycardia) completed the trial. Acute ablation was successful in 157 patients (99.37%). The skin-to-skin procedure time was 89.9±35.5 min. The median number of PFA discharges was 12 (8-19) with a median effective PFA discharge time of 4.6 (3.2-6.4) ms. Five patients (4 with atrioventricular reentrant tachycardia and 1 with Wolff-Parkinson-White syndrome) experienced paroxysmal supraventricular tachycardia recurrence during the 180-day follow-up period. One patient had a transient first-degree atrioventricular block resolving in 12 hours, and one patient had a transient third-degree atrioventricular block resolving in 24 hours. No permanent atrioventricular block or other adverse events occurred during the ablation procedure or 180-day follow-up period.

CONCLUSIONS

PFA demonstrated the feasibility of the treatment of SVT. Reversible first- and third-degree atrioventricular blocks were observed following ablation in one patient each. The preliminary results indicated the safety and feasibility of a combination of PFA and radiofrequency ablation treatment for atrioventricular accessory pathways although it is impossible to determine the relative contribution of PFA.

Mapping and ablation of ventricular tachycardia using dual-energy lattice-tip focal catheter: early feasibility and safety study

AIMS

Catheter ablation is an effective treatment method for recurrent ventricular tachycardias (VTs). However, at least in part, procedural and clinical outcomes are limited by challenges in generating an adequate lesion size in the ventricular myocardium. We investigated procedural and clinical outcomes of VT ablation using a novel 'large-footprint' catheter that allows the creation of larger lesions either by radiofrequency (RF) or by pulsed field (PF) energy.

METHODS AND RESULTS

In prospectively collected case series, we describe our initial experience with VT ablation using a lattice-tip, dual-energy catheter (Sphere-9, Medtronic), and a compatible proprietary electroanatomical mapping system (Affera, Medtronic). The study population consisted of 18 patients (aged 55 ± 15 years, one woman, structural heart disease: 94%, ischaemic heart disease: 56%, left ventricular ejection fraction: 34 ± 10%, electrical storm: 22%) with recurrent sustained VTs and ≥1 previously failed endocardial RF ablation with conventional irrigated-tip catheter in 66% of patients. On average, 12 ± 7 RF and 8 ± 9 PF applications were delivered per patient. In three-fourths of patients undergoing percutaneous epicardial ablation, spasms in coronary angiography were observed after PF applications. All resolved after intracoronary administration of nitrates. No acute phrenic nerve palsy was noted. One patient suffered from a stroke that resolved without sequelae. Post-ablation non-inducibility of VT was achieved in 89% of patients. Ventricular-arrhythmia-free survival at three months was 78%.

CONCLUSION

VT ablation using a dual-energy lattice-tip catheter and a novel electroanatomical mapping system is feasible. It allows rapid mapping and effective substrate modification with good outcomes during short-term follow-up.

Characterization and Clinical Significance of Hemolysis After Pulsed Field Ablation for Atrial Fibrillation: Results of a Multicenter Analysis

BACKGROUND

Pulsed field ablation (PFA) is increasingly used in clinical practice for the treatment of atrial fibrillation. While the susceptibility of erythrocytes to electroporation is well established, the effect of cardiac PFA technologies on hemolysis has remained underreported. The aim of this study was to investigate the incidence, severity, and clinical impact of PFA-induced hemolysis.

METHODS

We included n=145 patients undergoing atrial fibrillation catheter ablation with a pentaspline PFA catheter (biphasic, bipolar pulses of 2 kV) and n=70 patients receiving radiofrequency ablation (40-90 W) at 4 high-volume European centers. The lesion set comprised pulmonary vein isolation for paroxysmal atrial fibrillation and pulmonary vein isolation±additional lesions for persistent atrial fibrillation. Hemolysis and renal function biomarkers were analyzed in blood samples at baseline, at the end of ablation, and 24 hours after the procedure.

RESULTS

Baseline characteristics were well balanced between groups (overall mean 65.7±9.4 years; 69.3% men). The ablation procedures comprised a mean of 61.6±27.4 PFA deliveries and 26.3±15.0 minutes RF duration. Hemolysis was detected in 94.3% versus 6.8% of patients after PFA versus radiofrequency ablation (P<0.001): PFA was associated with significantly lower haptoglobin levels (0.5±0.4 versus 1.0±0.4 g/L), while free plasma hemoglobin (592.8±330.6 versus 147.8±183.0 mg/L), bilirubin (21.3±11.3 versus 14.8±8.8 µmol/L), and LDH (lactate dehydrogenase, 352.7±115.7 versus 253.2±56.5 U/L) were significantly higher after PFA compared with radiofrequency ablation (all P<0.001). Hemolysis correlated with the number of PFA deliveries (r=0.62 [95% CI, 0.33-0.80]; P<0.001), with the highest severity occurring ≥54 PFA deliveries. After PFA, hemoglobinuria occurred in 36.4%, while creatinine increase was higher in patients with baseline glomerular filtration rate <50 mL/min than with baseline glomerular filtration rate >50 mL/min (Δcrea, 27.0±103.1 versus -0.2±12.1 µmol/L; P=0.010).

CONCLUSIONS

Intravascular hemolysis is a frequent finding after PFA and increases with the number of PFA deliveries. Until the clinical impact of PFA-associated hemolysis is fully elucidated, a careful titration of PFA deliveries during the ablation procedure is warranted.

Meta-analysis of high-power short-duration versus cryoballoon ablation for atrial fibrillation

BACKGROUND

The existing literature regarding the treatment strategy for high-power short-duration (HPSD) ablation in patients diagnosed with atrial fibrillation (AF) is currently insufficient. The objective of this study is to perform a comparative analysis evaluating the effectiveness, safety, and procedural efficiency of HPSD versus cryoballoon ablation (CBA) for AF.

METHODS

A comprehensive search was conducted in PubMed, EMBASE, Cochrane Library, Scopus, Web of Science, and ClinicalTrials.gov databases to identify trials comparing HPSD with CBA for AF from their inception until December 25, 2023. Treatment effect measures were expressed as odds ratio (OR), mean difference (MD), accompanied by a 95% confidence interval (CI).

RESULTS

The analysis comprised six eligible trials involving a total enrollment of 2481 patients. No statistically significant disparities were observed in recurrent atrial arrhythmia (OR 0.90; 95% CI, 0.71-1.16) or total complications (OR 0.65; 95% CI, 0.38-1.12) between the two ablation techniques examined in this study. However, HPSD technique exhibited a significantly prolonged procedure time (MD 27.42; 95% CI, 19.03 to 35.81). Conversely, no significant differences were observed between the two modalities in terms of total fluoroscopy duration (MD -4.37; 95% CI -10.70 to 1.96) and ablation time (MD 7.95; 95% CI -3.97 to 19.88). Furthermore, HPSD demonstrated significantly higher odds of extrapulmonary vein (PV) trigger ablation compared to CBA (OR 18.86; 95% CI, 5.12-69.49). The subgroup analyses revealed that CBA continued to exhibit superior procedure time (except for the paroxysmal AF subgroup: [MD 29.52; 95% CI -4.25 to 63.60]), while no significant differences in safety and efficacy (except for the HPSD ≥ 70 W subgroup: [OR 0.44, 95% CI 0.20-0.97]) outcomes were still observed.

CONCLUSION

Among patients undergoing ablation therapy for AF, both HPSD and CBA demonstrate comparable efficacy and safety profiles; however, HPSD is associated with longer procedural time and higher rates of extra-PV trigger ablation.

Efficacy and safety of focal pulsed-field ablation for ventricular arrhythmias: two-centre experience

AIMS

A pulsed electric field (PF) energy source is a novel potential option for catheter ablation of ventricular arrhythmias (VAs) as it can create deeper lesions, particularly in scarred tissue. However, very limited data exist on its efficacy and safety. This prospective observational study reports the initial experience with VA ablation using focal PF.

METHODS AND RESULTS

The study population consisted of 44 patients (16 women, aged 61 ± 14years) with either frequent ventricular premature complexes (VPCs, 48%) or scar-related ventricular tachycardia (VT, 52%). Ablation was performed using an irrigated 4 mm tip catheter and a commercially available PF generator. On average, 16 ± 15 PF applications (25 A) were delivered per patient. Acute success was achieved in 84% of patients as assessed by elimination of VPC or reaching non-inducibility of VT. In three cases (7%), a transient conduction system block was observed during PF applications remotely from the septum. Root analysis revealed that this event was caused by current leakage from the proximal shaft electrodes in contact with the basal interventricular septum. Acute elimination of VPC was achieved in 81% patients and non-inducibility of VT in 83% patients. At the 3-month follow-up, persistent suppression of the VPC was confirmed on Holter monitoring in 81% patients. In the VT group, the mean follow-up was 116 ± 75 days and a total of 52% patients remained free of any VA.

CONCLUSION

Pulsed electric field catheter ablation of a broad spectrum of VA is feasible with acute high efficacy; however, the short-term follow-up is less satisfactory for patients with scar-related VT.

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.

Periprocedural myocardial infarction and injury

Periprocedural myocardial infarction (PMI) and injury, pertinent to both cardiac and non-cardiac procedures, have gained increasing recognition in clinical practice. Over time, diverse definitions for diagnosing PMI have been developed and validated among patient populations undergoing coronary revascularization. However, this variety in definitions presents considerable challenges in clinical settings and complicates both the design and interpretation of clinical trials. The necessity to accurately diagnose PMI has spurred significant interest in establishing universally accepted and prognostically meaningful thresholds for cardiac biomarkers elevation and supportive ancillary criteria. In fact, elevations in cardiac biomarkers in line with the 4th Universal Definition of Myocardial Infarction, have been extensively confirmed to be associated with increased mortality and cardiovascular events. In the context of non-coronary cardiac procedures, such as Transcatheter Aortic Valve Implantation, there is a growing acknowledgment of both the high incidence rates and the adverse impact of PMI on patient outcomes. Similarly, emerging research underscores the significance of PMI and injury in non-cardiac surgery, highlighting the urgent need for effective prevention and risk management strategies in this domain.