Safety and Effectiveness of a Novel Dual-Energy Radiofrequency/Pulsed Field Ablation Catheter: 12 Month Results of the FlexPulse Study.

BACKGROUND AND AIMS: Pulsed field (PF) ablation is increasingly used to treat paroxysmal atrial fibrillation (PAF). FlexPulse (NCT06676072) was conducted to evaluate safety and effectiveness of a novel dual-energy, flexible-tip focal ablation catheter with radiofrequency and PF for treatment of symptomatic, drug-refractory PAF. METHODS: FlexPulse was a global, prospective, single arm, multicentre study. The ablation procedures targeted pulmonary vein isolation (PVI) and adjunctive ablation at operators' discretion. The primary safety endpoint was occurrence of pre-defined safety events within 7-days of any ablation procedure. The primary effectiveness endpoint was freedom from a composite of recurrent AF/atrial tachycardia/atrial flutter, repeat procedure, new use or escalation of class I/III AAD, and/or cardioversion through 12-months. RESULTS: Overall, 180 subjects underwent PAF ablation. Successful PVI was achieved in all participants. Additional non-PV ablations were performed in 37.2% (67/180) of subjects. The primary safety endpoint event rate was 1.7%. The primary effectiveness endpoint was 74.6% at 12-months, and freedom from documented AF/AFL/AT recurrence was 77.4% (92.6% without weekly transtelephonic monitoring). In 15 subjects who underwent repeat ablation after the blanking period, remapping indicated that 79.7% (47/59) of the PVs were durably isolated from the index procedures. Retrospective analysis found that workflows with PFA Index (PI) ≥30 and AutoMark distance up to 6 mm target had a 12-month freedom from AF/AFL/AT of 84.6%. CONCLUSIONS: In this trial, ablation with TactiFlex Duo in patients with symptomatic, drug-refractory PAF was safe and effective.