Ablation outcomes after PVI with PFA vs. CBA using alternative success definitions - insights from the SINGLE-SHOT CHAMPION trial using Continuous rhythm monitoring

Background Recurrence after atrial fibrillation (AF) ablation is commonly defined as any atrial arrhythmia lasting ≥30 seconds. Alternative efficacy endpoints of AF burden >0.1% and episode duration >1h have been proposed after thermal ablation that better associate to patient outcomes. It is unclear how these endpoints relate to patient outcomes after pulsed field ablation (PFA) as opposed to cryoballoon ablation (CBA). Methods Patients with symptomatic paroxysmal AF were randomized 1:1 to PVI using PFA or CBA. All patients received an implantable cardiac monitor (ICM) at the time of ablation, and the BP duration was 90 days. Results The primary endpoint of any recurrence lasting ≥30 seconds occurred in 37.1% in PFA and 50.7% in CBA. With an endpoint definition of a duration of at least 1h, recurrence was observed in 25.7% with PFA and in 32.8% in CBA. With an endpoint definition of an AF burden >0.1%, this endpoint occurred in 25.7% with PFA and in 29.5% in CBA (Figure 1). Rates of redo ablations increased more significantly for AF-episode durations >1 hour for PFA and >6h for CBA, and for AF-burden >0.1% after PFA and >1% after CBA (Figure 2 A & B) Conclusion In patients undergoing PVI, recurrence rates vary highly according to the success definition used for both PFA and CBA. For PFA, redo procedures maybe triggered even with lower AF burden and shorter episodes, potentially because of a potential clinician interest to remap or reintervene after PFA procedures.