Bipolar linear PFA shows similar safety to RFA for CTI ablation in persistent atrial fibrillation

BACKGROUND: ADVANTAGE AF examined the safety and efficacy of pulsed field ablation (PFA) to treat persistent atrial fibrillation (AF). During AF ablation, typical atrial flutter (AFL) is commonly treated with cavotricuspid isthmus (CTI) ablation. OBJECTIVES: Adjunctive CTI ablation in ADVANTAGE AF was performed with radiofrequency ablation (RFA; phase 1) or bipolar linear PFA (phase 2). Here, we compared lesion characteristics, CTI ablation efficacy, and safety between the ablation modalities. METHODS: A preclinical study assessed lesion dimensions with a novel 2.0 kV bipolar linear PFA catheter. In ADVANTAGE AF, after AF ablation with a pentaspline PFA catheter, CTI ablation was performed: in phase 1 with irrigated RFA, and in phase 2 with the linear PFA catheter (Farapoint). Before PFA CTI ablation ,patients were treated with a vasopressor bolus followed by high-dose intravenous nitroglycerin. RESULTS: Preclinical assessment showed lesion depth increasing at higher field strength and plateauing after 2 applications. In ADVANTAGE AF, 50 and 141 patients received CTI ablation with RFA and PFA, respectively. Patient characteristics across the 2 cohorts were similar (RFA vs PFA). Acute CTI conduction block was similar between techniques (50 of 50 RFA [100%] vs 139 of 141 PFA [98.6%]; P = 1.00). PFA was associated with a shorter CTI ablation time (median: RFA 5 min [Q1-Q3: 4-8 min] vs 14 min [Q1-Q3: 9-19 min]; P = 0.001). RFA and PFA had similar safety event rates (RFA 2.0% vs PFA 2.1%; P = 0.96). With the use of nitroglycerin pretreatment, there was no clinical manifestation of coronary artery spasm with PFA. CONCLUSIONS: This subanalysis of ADVANTAGE AF extends the primary results by allowing comparison of bipolar linear PFA and RF ablation for CTI, integrating preclinical lesion modeling with clinical dosing, and establishing a standardized reliable coronary safety protocol. Although not randomized comparisons, these findings suggest that CTI ablation with a linear PFA catheter is associated with safety and efficacy similar to RF ablation and greater efficiency. (A Prospective Single Arm Open Label Study of the FARAPULSE Pulsed Field Ablation System in Subjects With Persistent Atrial Fibrillation [ADVANTAGE AF; NCT05443594]).