Augmented Ablation Adds No Benefit in Prevention of Recurrent Atrial Arrhythmia

Girish M. Nair, MBBS, MSc

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An ablation strategy using routine delivery of a second circumferential line of ablation did not show additional benefit in preventing atrial arrhythmia recurrence in patients with paroxysmal atrial fibrillation (AF), according to new findings.¹

Investigators from the University of Ottawa Heart Institute, led by Girish M. Nair, MBBS, MSc, thus suggested the potential for a ceiling effect to the single procedure success of catheter ablation in patients with paroxysmal AF.

“​​This is consistent with prior research in catheter ablation in patients with persistent AF, where empirical adjunctive ablation strategies failed to reduce AA recurrence,” Nair and colleagues wrote.

Recurrent AF often occurs after catheter ablation and has been associated with both patient morbidity and high healthcare costs. Nair and colleagues looked to compare the standard of care ablation technique of adenosine-guided wide-area circumferential ablation (WACA) with a novel augmented WACA technique. The team hypothesized that the wider area of atrial ablation would increase the change of durable pulmonary vein isolation and thus result in the reduction of atrial arrhythmias including atrial tachycardia, atrial flutter, or AF, without affecting procedural safety.

The pragmatic, prospective, randomized, open, blinded endpoint Augmented Wide Area Circumferential Catheter Ablation for Reduction of Atrial Fibrillation Recurrence (AWARE) trial enrolled patients at 10 university-affiliated centers in Canada from March 2015 to May 2017. Individuals included in the study were 18 years and older with symptomatic paroxysmal AF (refractory to, intolerant of, or unwilling to trial antiarrhythmic drugs). Analysis occurred between January – April 2022.

The population of 398 patients was randomized 1:1 to receive radiofrequency catheter ablation for pulmonary vein isolation with either a standard single WACA (n = 195, 49%) or an augmented double WACA (n = 203, 51%). Overall, 52 patients (26.7%) in the control arm and 50 patients (24.6%) in the experimental arm had recurrent atrial arrhythmia at 1 year (relative risk [RR], 0.92; 95% CI, 0.66 - 1.29; P = .64).

Data showed 20 of 195 (10.3%) in the control arm and 15 of 203 patients (7.4%) in the experimental arm underwent repeated catheter ablation due to symptomatic atrial arrhythmia recurrence (RR, 0.72; 95% CI, 0.38 - 1.36). Investigators found no differences in atrial arrhythmia or atrial arrhythmia-related emergency department visits or hospitalizations between the 2 arms of the trial.

Quality of life and patient satisfaction score outcomes showed no significant difference in outcomes between the 2 treatment arms, according to the data. Additional subgroup analysis investigating the influence of high-power ablation showed no difference between the primary outcomes in those undergoing high-power ablation versus those undergoing ablation using standard settings. Safety was reported, with investigators noting adjudicated serious adverse events occurred in 13 patients (6.7%) in the control arm and 14 patients (6.9%) in the experimental arm.

Once more, investigators noted the results suggest a ceiling effect to the single procedure success of empirical WACA in a population with paroxysmal AF. Potential success and adverse event rates can potentially be used for shared decision-making with patients.

“The experimental strategy using additional ablation lesions did not reduce the recurrence of atrial arrhythmia,” they wrote. “This suggests that more is not necessarily better when it comes to ablation of paroxysmal AF.”

References

1. Nair GM, Birnie DH, Nery PB, et al. Standard vs Augmented Ablation of Paroxysmal Atrial Fibrillation for Reduction of Atrial Fibrillation Recurrence: The AWARE Randomized Clinical Trial. JAMA Cardiol. Published online March 22, 2023. doi:10.1001/jamacardio.2023.0212