Pulsed-Field Ablation to Enhance the Durability of Pulmonary Vein Isolation and Treat Paroxysmal Atrial Fibrillation.

Abstract

In first-in-human studies of the treatment of paroxysmal atrial fibrillation (PAF), a multielectrode globular spherical array pulsed field ablation (PFA) catheter and system able to map, pace, sense contact, and ablate exhibited a high rate, 94%, of durable pulmonary vein isolation (PVI). In this study, the authors sought to assess the 1-year outcomes of a multicenter single-arm pivotal trial of the spherical array system to treat PAF. In the multicenter PULSAR pivotal investigational device exemption trial, patients with symptomatic drug-resistant or intolerant PAF underwent PVI with the use of the spherical array system. The array catheter was used to render left atrial anatomy and voltage and perform PVI. The primary effectiveness endpoint was a composite of 12-month freedom from atrial arrhythmias (as assessed by weekly and symptomatic transtelephonic monitoring and 24-hour Holter monitoring) and freedom from other failure modes: failure to achieve PVI, repeated ablation or cardioversion, and the use of new or increased doses of class I or III antiarrhythmic drugs. The primary safety endpoint included primary adverse events within 7 days of the index ablation procedure. The study cohort of 183 patients included 19 roll-in and 164 pivotal patients: aged 65 ± 9.1 years, 40% female, CHA₂DS₂-VASc 2.1 ± 1.4, left atrial diameter 3.8 ± 0.6 cm. Mapping time (9.0 ± 5.5 min), transpired ablation time (25.6 ± 9.8 min), left atrial catheter dwell time (59.9 ± 11.6 min), and procedure time (95.8 ± 20.7 min) revealed an efficient procedure. Most pulmonary veins (PVs) (94%, 607/647 veins) were electrically isolated by the first pulsed field application. The primary safety event rate was 0.6% (1/164): a hemorrhagic stroke identified immediately after the procedure in a patient with severe hypertension and polycystic kidney disease. The PV stenosis substudy revealed no patients with moderate or severe vein narrowing. Primary effectiveness at 12 months was 77.8% (95% CI: 70.6%-83.9%). During redo ablation in 11 patients, 39 of 41 (95.1%) pulmonary veins remained durably isolated. The favorable clinical success observed in this multicenter Food and Drug Administration trial of this novel PFA catheter appears to reflect the clinical success achievable with durable PVI in PAF patients. (Safety and Effectiveness of the Globe Pulsed Field System for Treating Patients with Symptomatic Paroxysmal or Persistent Atrial Fibrillation [PULSAR]; NCT05462145).