Double Wide-Area Ablation and Recurrent Atrial Arrhythmias in Atrial Fibrillation

Double wide-area circumferential ablation (WACA), compared with standard single WACA, does not prevent recurrent atrial arrhythmias (AA) in patients with paroxysmal atrial fibrillation (AF), according to findings published in the Journal of the American Medical Association Cardiology.

Researchers in Canada sought to compare prevention of recurrent atrial tachycardia, atrial flutter, or AF following double WACA vs standard single WACA in patients with paroxysmal AF. The primary endpoint was recurrence of atrial arrhythmia 91 to 365 days postablation. Need for repeated catheter ablation, along with procedural and safety variables, represented secondary endpoints. The hypothesis was that the chance of durable pulmonary vein isolation (PVI) would be increased by the wider area of atrial ablation resulting in atrial arrhythmia reduction.

The researchers conducted the prospective, multicenter, randomized, blinded AWARE trial (ClinicalTrials.gov Identifier: NCT02150902) in Canada at 10 university-affiliated centers. Patients aged at least 18 years with symptomatic paroxysmal AF were enrolled from March 2015 to May 2017. The researchers included 398 patients who received radiofrequency catheter ablation for PVI after being randomly assigned in a 1:1 ratio for either the double WACA experimental arm (n=203; mean age, 61.5±9.3 years; 32.5% women; 40.9% hypertension) or the single WACA control arm (n=195; mean age, 60.6±9.3 years; 33.3% women; 42.1% hypertension).

Prior to ablation, antiarrhythmic drug use was discontinued. Following ablation, patients received 6 weeks of ambulatory monitoring with electrocardiography, and no antiarrhythmic drugs were used during the 90-day blanking period. No patients received antiarrhythmic drugs during the 91- to 365-day period following ablation. Intention-to-treat analyses occurred between January and April 2022.

Following catheter ablation in the control arm, 52 patients (26.8%) experienced dormant pulmonary vein conduction requiring additional ablation. In all patients, electrophysiologic testing was used to confirm bidirectional conduction block across all pulmonary veins.

There were 50 patients (24.6%) in the experimental arm and 52 patients (26.7%) in the control arm that experienced recurrent atrial arrhythmia at 1 year (relative risk [RR], 0.92; 95% CI, 0.66-1.29; P =.64). There were 15 patients (7.4%) in the experimental arm and 20 patients (10.3%) in the control arm who received repeated catheter ablation (RR, 0.72; 95% CI, 0.38-1.36). There were 14 patients (6.9%) in the experimental arm and 13 patients (6.7%) in the control arm with adjudicated serious adverse events. There was no difference between study arms regarding atrial arrhythmia-related emergency department visits or hospitalizations and no significant difference between arms in patient satisfaction scores or quality of life.

There was no influence on trial results with prespecified subgroup analyses. There was no difference in any primary outcome between patients who received high-power ablation (radiofrequency energy ≥45W) vs patients who received standard radiofrequency energy settings. Comparing the University of Ottawa site vs all other centers combined showed no difference in primary outcomes.

Significant study limitations include the insufficient sample size and lack of generalizability.

“In patients with paroxysmal AF, an ablation strategy using routine delivery of a second circumferential line of ablation did not show any additional benefit in preventing AA [atrial arrhythmia] recurrence at 1 year,” the researchers wrote. “This is consistent with prior research in catheter ablation in patients with persistent AF, where empirical adjunctive ablation strategies failed to reduce AA recurrence.”

Disclosure: This research was supported by Biosense Webster, part of the Johnson & Johnson Family of Companies. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.