BACKGROUND

The ADVENT randomized trial revealed no significant difference in 1-year freedom from atrial arrhythmias (AA) between thermal (radiofrequency/cryoballoon) and pulsed field ablation (PFA). However, recent studies indicate that the postablation AA burden is a better predictor of clinical outcomes than the dichotomous endpoint of 30-second AA recurrence.

OBJECTIVES

The goal of this study was to determine: 1) the impact of postablation AA burden on outcomes; and 2) the effect of ablation modality on AA burden.

METHODS

In ADVENT, symptomatic drug-refractory patients with paroxysmal atrial fibrillation underwent PFA or thermal ablation. Postablation transtelephonic electrocardiogram monitor recordings were collected weekly or for symptoms, and 72-hour Holters were at 6 and 12 months. AA burden was calculated from percentage AA on Holters and transtelephonic electrocardiogram monitors. Quality-of-life assessments were at baseline and 12 months.

RESULTS

From 593 randomized patients (299 PFA, 294 thermal), using aggregate PFA/thermal data, an AA burden exceeding 0.1% was associated with a significantly reduced quality of life and an increase in clinical interventions: redo ablation, cardioversion, and hospitalization. There were more patients with residual AA burden <0.1% with PFA than thermal ablation (OR: 1.5; 95% CI: 1.0-2.3; P = 0.04). Evaluation of outcomes by baseline demographics revealed that patients with prior failed class I/III antiarrhythmic drugs had less residual AA burden after PFA compared to thermal ablation (OR: 2.5; 95% CI: 1.4-4.3; P = 0.002); patients receiving only class II/IV antiarrhythmic drugs pre-ablation had no difference in AA burden between ablation groups.

CONCLUSIONS

Compared with thermal ablation, PFA more often resulted in an AA burden less than the clinically significant threshold of 0.1% burden. (The FARAPULSE ADVENT PIVOTAL Trial PFA System vs SOC Ablation for Paroxysmal Atrial Fibrillation [ADVENT]; NCT04612244).