Comparison Between Extended Cryoablation, Standard Cryoablation, and Radiofrequency Ablation (EXCAPE-AF)

Asan Medical Center

Status: Completed

Conditions: Atrial Fibrillation, Persistent

Treatments: Procedure: Extended cryoballoon ablation; Procedure: Radiofrequency ablation; Procedure: Standard cryoballoon ablation

Study type: Interventional

Funder types: Other

Identifiers

NCT07034378

AMC2020-1896

Details and patient eligibility

About

The objective of this study is to test the efficacy hypothesis that extended cryoballoon ablation is superior to either standard cryoballoon ablation or radiofrequency ablation

Full description

The posterior wall of the left atrium is known to contribute to arrhythmogenicity and has been associated with higher rates of atrial fibrillation (AF) recurrence. In this trial, we aim to evaluate whether extended cryoballoon ablation-comprising pulmonary vein isolation (PVI) plus posterior wall isolation-results in superior rhythm outcomes compared to standard cryoballoon ablation (PVI only) or radiofrequency ablation (PVI only). Patients will be randomly assigned to one of three treatment arms: extended cryoballoon ablation, standard cryoballoon ablation, or radiofrequency ablation. Each patient will receive the assigned treatment accordingly. The primary outcome is the incidence of atrial tachyarrhythmias-including atrial fibrillation, atrial flutter, and atrial tachycardia-lasting more than 30 seconds, occurring after discontinuation of antiarrhythmic drugs and following a 3-month post-procedure blanking period. Outcomes will be compared at 1 year after the procedure.

Enrollment: 288 patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients aged between 18-80 years
• Patients with persistent (≥7 days) AF documented on 12-lead ECG or Holter monitoring.
• AF refractory/intolerant to class I or III antiarrhythmic drugs
• Able and willing to provide written informed consent to CB or RF ablation and participation in this investigation

Exclusion criteria

• Age <18 years old or >80 years old
• Paroxysmal AF lasting <7 days
• Mitral stenosis or mechanical prosthetic valve
• Patients with left atrial size ≥ 50 mm (2D echocardiography, Anterior-posterior diameter in parasternal long axis view)
• Anatomy of pulmonary vein not suitable for standard CB or extended CB, including common ostium or ostium size > 26mm
• Pregnant woman of childbearing age with a positive pregnancy test before treatment
• Presence of atrial septal defect or patent foramen ovale closure device
• Presence of intracardiac thrombus
• Contraindications to the systemic anticoagulation
• NYHA functional class IV heart failure
• Prior catheter or surgical ablation of AF
• Acute coronary syndrome within 3 months
• Planned open heart surgery within 3 months
• Prior open-heart surgery within 3 months
• End stage renal disease or chronic kidney disease (estimated glomerular filtration rate [MDRD method] < 30mL/min/1.73m²)
• Life expectancy less than 1 year.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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288 participants in 3 patient groups

Extended cryoballoon ablation

Experimental group

Description:

The method of ablation, size of balloon, freezing time, and booster freezing will be decided by the participating center's policy or physician's discretion. Ablation strategies described above are highly recommended for all participants. Additional posterior wall isolation should be performed by single 120 to 180 second CB application delivered at each site. Maximal posterior wall debulking should be attempted, although complete isolation may not always be achievable, as we considered that a large scar created by the CB application would provide sufficient anti-arrhythmic effects in terms of suppressing AF. The number and duration of CB application should be recorded in the case report form. Successful posterior wall isolation should be determined by 3-dimensional electro-anatomical mapping or differential pacing. The method and achievement of posterior wall isolation should be recorded in the case report form.

Treatment:

Procedure: Extended cryoballoon ablation

Standard cryoballoon ablation

Active Comparator group

Description:

Application of TTI + 2 minutes or 180 seconds single-freezing is recommended when time-to-isolation (TTI) \<60 seconds. Additional 120 seconds of booster-freezing after TTI + 2 or 180 seconds initial freezing is recommended when TTI value \>60 seconds, or PV potentials were not discernable in the Achieve multipolar catheter. If temperatures below -40°C cannot be achieved due to improper occlusion or TTI \> 90 seconds, freezing should be discontinued and reposition of balloon is recommended. Segmental ablation is allowed when the proper occlusion of PV by balloon cannot be achieved. Continuous phrenic capture should be monitored during the procedure in the right PVs to avoid phrenic nerve injury. Stop ablation immediately if phrenic nerve damage is suspected. No further ablation would be performed if the phrenic nerve damage is suspected. Touch-up ablation using irrigated radiofrequency ablation catheter would be permitted with conventional mapping method.

Treatment:

Procedure: Standard cryoballoon ablation

Radiofrequency ablation

Active Comparator group

Description:

CARTO system (Biosense-Webster, USA): Ablation index (AI) CLOSE protocol . Navistar Smart-touch surround-flow catheter; 25-40 watts of energy; 40 seconds time limit; 10-30 gram of contact force; 40 seconds time limit; targeting AI value of 550 in anterior wall and 400 in the posterior wall; interlesion distance ≤6mm; using automatic lesion annotation (Visitag™) - type 3 tagging, 3mm stability for 5 seconds, force \>5g over 50% of time; target AI value could be reduced (450 in anterior wall and 350 in posterior wall) according to the participating center's policy. Ensite NavX system (Abbott, USA) : TactiCath™ Quartz ablation catheter; delivering 25-35 watts of energy; 40 seconds time limit; 10-30 gram of contact force; using automatic lesion annotation (Automark Module), target lesion index value of 5-5.5 in the posterior wall and 5.5-6 in the anterior wall.

Treatment:

Procedure: Radiofrequency ablation