Initial clinical experience of pulmonary vein isolation using the ultra-low temperature cryoablation catheter for patients with atrial fibrillation

Acute Procedural Results of Pulsed Field Cryoablation for Persistent Atrial Fibrillation: Multicenter First-in-Human PARALELL Trial

INTRODUCTION

Pulsed Field Cryoablation (PFCA) is a dual-energy cardiac ablation modality consisting of short-duration ultra-low temperature cryoablation (ULTC) followed immediately by pulsed field ablation (PFA) delivered from the same catheter. It is hypothesized that PFCA may improve contact stability during PFA, while maintaining lesion depth and effectiveness of ULTC.

METHODS

PARALELL is a first-in-human multicenter study evaluating safety and effectiveness of a novel PFCA catheter and system in patients with persistent atrial fibrillation (PsAF) using the combination of pulmonary vein (PVI) and posterior wall (PWI) isolation.

RESULTS

Sixty-six patients were ablated at six sites. One groin hematoma and one intubation-related hospitalization were the only serious procedure- or device-related adverse events recorded in the study. Per protocol, acute effectiveness was evaluated in 46 patients, including 31 patients with post-hoc analysis of cryogenic energy per lesion. After an average of 21.1 ± 9.3 lesions per patient the rates of PVI and PWI were 95.7% (176/184) and 97.7% (42/43), respectively. The average cryogenic energy per patient was highly predictive of acute isolation success with ROC AUC = 0.944% and 100% rates of both PVI and PWI in 24 patients in the optimal energy cohort. Grade I microbubbles and faint muscle contractions were detected in 1.1% and 0.5% of ablations, respectively.

CONCLUSION

This initial multi-center experience suggests that PFCA can be efficiently performed for PVI and PWI using a single versatile catheter system, with high acute success and good early safety profile. The evaluation of the chronic 12-month effectiveness of PFCA is ongoing.

Durability of Ultra-Low Temperature Cryoablation Lesions in Atrial Fibrillation: Insights From Repeat Ablation Procedures

BACKGROUND

Ultra-low temperature cryoablation (ULTC) is a technique designed to rapidly cool cardiac tissue to extremely low temperatures, enabling the creation of ablation lesions for the treatment of atrial fibrillation (AF). Prior studies have demonstrated low rates of arrhythmia recurrence, but little is known about ablation lesion durability.

METHODS

Patients undergoing repeat ablation were selected from the CryoCure2 (NCT02839304) and iCLAS PMCF(NCT05416086) studies. Baseline patient and ULTC procedure characteristics were evaluated. During repeat ablation, ULTC ablation lesions were assessed for electrical block, including segment-based assessment of pulmonary vein (PV) ablation lesions. Arrhythmia outcomes after repeat ablation were evaluated.

RESULTS

Twenty-five patients were included in the cohort: Age 68 ± 7 years, male 68%, persistent AF 68%, LAVI 42 ± 24 mL/m2. During index procedure, ULTC was used to target the PVs in all patients, the left atrium posterior wall (LAPW) in 15 patients, the lateral mitral isthmus (LMI) in five patients and the cavotricuspid isthmus (CTI) in two patients. At repeat ablation, PV reconnection was observed in 21/25 patients (55/100 PVs reconnected), and reconnection occurred most often in the anterior segments of the left PVs. The LAPW lesion was incomplete in 4/15 patients, the LMI in 3/5 and the CTI in 1/2. After repeat ablation, 10/25 patients had arrhythmia recurrence.

CONCLUSION

Reconnection of ablation targets during repeat ablation for arrhythmia recurrence following ULTC occurred at rates comparable to those observed with conventional thermal ablation modalities. The anterior side of the left PVs appears to be reconnected most often.

Comparative analysis of anaesthesia modalities in pulmonary vein isolation: insights from a prospective multicentre registry

AIMS

Atrial fibrillation (AF), the most common sustained arrhythmia in adults, is increasing in prevalence globally. Catheter ablation (CA), particularly pulmonary vein isolation (PVI), is a key treatment option. Pulmonary vein isolation can be performed using different energy sources, including cryoballoon ablation (CBA), radiofrequency ablation (RFA), or pulse field ablation. Anaesthesia modalities for these procedures include general anaesthesia (GA), deep sedation (DS), and conscious sedation (CS). However, the optimal anaesthesia modality remains unclear, as previous studies have shown mixed outcomes. This study aims to compare the safety and efficacy of different anaesthesia modalities in PVI.

METHODS AND RESULTS

This prospective, multicentre study, based on the Israeli Catheter Ablation Registry, evaluated the impact of different anaesthesia modalities on procedural outcomes and safety in AF ablation. Data from 1002 patients who underwent PVI between January 2019 and December 2021 across 14 centres were analysed. Patients were stratified by anaesthesia modality-CS vs. GA, with the latter encompassing DS. Key outcomes, including AF recurrence, procedural complications, and success rates, were evaluated over a 24-month follow-up period. Additionally, a sensitivity analysis was performed for the subgroup of patients who underwent CBA. Of the 1002 patients, 53% received GA, 6.3% DS, and 40% CS, with CBA used in 84% of cases. Complete PVI was achieved in 91% of patients, with comparable success rates observed between CS and GA groups. No significant differences were found between CS and GA modalities in terms of AF recurrence rates at 12 months (15% vs. 16%) and 24 months (19.5% vs. 21.2%), or in 12-month rehospitalization rates (19.8% vs. 16.5%). Sensitivity analysis of the CBA subgroup yielded similar results, with no significant differences in AF recurrence, complications, or procedural duration between CS and GA modalities.

CONCLUSION

Conscious sedation is as safe and effective as general anaesthesia in AF ablation, particularly with cryoablation. The choice of anaesthesia appears to be driven by patient characteristics and institutional factors without affecting long-term outcomes such as AF recurrence or complication rates.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Progress in atrial fibrillation ablation during 25 years of Europace journal

The first edition of Europace journal in 1999 came right around the time of the landmark publication of the electrophysiologists from Bordeaux, establishing how elimination of ectopic activity from the pulmonary veins (PVs) resulted in a marked reduction of atrial fibrillation (AF). The past 25 years have seen an incredible surge in scientific interest to develop new catheters and energy sources to optimize durability and safety of ablation, as well as study the mechanisms for AF and devise ablation strategies. While ablation in the beginning was performed with classic 4 mm tip catheters that emitted radiofrequency (RF) energy to create tissue lesions, this evolved to using irrigation and contact force (CF) measurement while increasing power. Also, so-called single-shot devices were developed with balloons and arrays to create larger contiguous lesions, and energy sources changed from RF current to cryogenic ablation and more recently pulsed field ablation with electrical current. Although PV ablation has remained the basis for every AF ablation, it was soon recognized that this was not enough to cure all patients, especially those with non-paroxysmal AF. Standardized approaches for additional ablation targets have been used but have not been satisfactory in all patients so far. This led to highly technical mapping systems that are meant to unravel the drivers for the maintenance of AF. In the following sections, the development of energies, strategies, and tools is described with a focus on the contribution of Europace to publish the outcomes of studies that were done during the past 25 years.

Cryoablation as a first-line therapy for atrial fibrillation: current status and future prospects

INTRODUCTION

Atrial fibrillation (AF) is a common chronic and progressive heart rhythm disorder. For those in whom sinus rhythm is desired, contemporary clinical practice guidelines recommend antiarrhythmic drugs (AADs) as the initial therapy. However, these medications have modest efficacy and are associated with significant adverse effects.

AREAS COVERED

The current article reviews the evidence surrounding first line catheter ablation, particularly the emerging evidence surrounding the use of cryoballoon ablation as a first-line therapy. The focus of the review is on the outcomes of arrhythmia freedom, quality of life, healthcare utilisation and safety. In addition, the article will review novel cryoablation systems.

EXPERT OPINION

: Recent evidence suggests that cryoballoon ablation significantly improves arrhythmia outcomes (e.g., freedom from any atrial tachyarrhythmia or symptomatic atrial tachyarrhythmia, reduction in arrhythmia burden), patient-reported outcomes (e.g., symptoms and quality of life), and healthcare resource utilization (e.g., hospitalization), without increasing the risk of adverse events. These findings are relevant to patients, providers, and healthcare systems, as it helps inform the decision-making regarding the initial choice of rhythm-control therapy in patients with treatment-naïve AF.