Durability of pulmonary vein isolation with pulsed field ablation compared to radiofrequency ablation in patients with persistent atrial fibrillation: results from a prospective remapping study
Authors: Galuszka O , Baldinger S , Kueffer T , Servatius H , Madaffari A , Kozhuharov N , Thalmann G , Herrera Siklody C , Maurhofer J , Haeberlin A , Noti F , Tanner H , Reichlin T , Roten L 
Published: May 2024

Abstract

Background
Pulsed field ablation (PFA) is a novel technology used for pulmonary vein isolation (PVI). Durability of PVI is critical to avoid atrial fibrillation (AF) recurrence. There is little data available on durability of PVI with PFA as compared to radiofrequency ablation (RFA), and on the mechanisms of arrhythmia recurrence in patients with persistent AF.

Objective
To invasively assess the durability of PVI with PFA compared to RFA using mandatory remapping studies after 6 months.

Methods
In a prospective study we included patients with symptomatic persistent AF to undergo a first PVI by either CLOSE protocol-guided RFA or PFA. Irrespective of AF recurrence, a remapping procedure was mandated 6-8 months following the index procedure to invasively evaluate PVI durability. The outcome of AF ablation was based on clinical recurrence and 7-day Holter-ECGs 3 and 6 months after the index procedure. Arrhythmia recurrence was defined as any atrial arrhythmia episode longer than 30 seconds beyond the 3-month blanking period.

Results
60 patients (82% male; median age 68 years [60 – 74], median LAVI 47 ml/m2 [38 – 51]) undergoing PVI for persistent AF (median duration: 5 months [IQR: 3 – 9.5]) were included (30 in RFA group vs. 30 in PFA group). Procedure time was longer in the RFA group (169±39 min vs. 114±33 min, p&lt;0.001), with longer fluoroscopy time in the PFA group (7.7±6.0 min vs. 19.7±7.5 min, p&lt;0.001). Acute PVI was achieved in all 241 veins (100%) and no procedural complications were observed in either group. A median of 7.2 months after the index procedure 49 out of 60 patients underwent the remapping study (26 in RFA and 23 in PFA group; with some remapping procedures pending at the time of abstract submission). In the RFA group 78 out of 102 (76%) pulmonary veins (PVs) showed persistent isolation, compared to 74 out of 95 (78%) PVs in the PFA group (p=0.726). 15/26 (58%) RFA and 11/23 (48%) PFA group patients presented complete isolation of all PVs (p=0.594). Recurrence of arrhythmia was observed in 6/26 (23%) RFA and in 7/23 (30%) PFA group patients (p=0.542). Recurrence of persistent AF, paroxysmal AF, and atrial tachycardia was similar in both groups (RFA: 6 / 0 / 0; PFA: 5 / 1 / 1; p=0.612). In the pooled cohort, arrhythmias recurred irrespective of PV isolation status, in 7/26 (27%) patients with complete PVI vs. 6/23 (26%) patients with reconnected PVs (p=0.947). Similarly, the proportion of durably isolated PVs was not different in patients with (7/13; 54%) and without arrhythmia recurrence (19/36; 53%; p=0.947).

Conclusions
In patients with persistent AF undergoing mandated remapping procedure, we found comparable rates of durable PVI with RFA and PFA, both on a per-patient and a per-vein level. PVI with PFA was faster than RFA but required longer fluoroscopy time. Recurrence of AF was independent of durable PV isolation, underlining the need for additional ablation targets in a subset of patients with persistent AF.