Background:

Pulsed Field Ablation (PFA) is a promising new ablation technology for atrial fibrillation. PFA can be performed "cryo-style" using fluoroscopy only, or additional pre- and post-ablation high-density 3D bipolar voltage maps can be madeto assess lesion formation and acute pulmonary vein isolation (PVI). We compared acute outcome after PFA using fluoroscopy only (X-ray group) vs. PFA guided by 3D mapping (3D group).

Methods:

Consecutive AF patients underwent PFA-based PVI using a steerable sheath and a pentaspline, over-the-wire PFA catheter (Farapulse, Boston Scientific). In a subset of patients, pre- and post-ablation high-density bipolar voltage 3D maps (Biosense Webster Carto 3D) were performed (Figure). Procedural parameters, acute success and in-hospital safety were assessed.

Results:

A total of 422 patients (mean age 67 years (range 35–87), female 41%, mean BMI 27 kg/m2 (range 18-43), mean CHA2DS2-VASc score of 2 (range 0-7), paroxysmal AF/persistent AF 79%/21%) underwent a first PVI. Mean duration since first AF diagnosis was 45 months (range 1-331). Pre- and post-ablation, high-density maps were performed randomly in 24% of cases. Skin-to skin procedure time was 48±14 min in the X-ray group vs. 120±30 min in the 3D group, respectively (p<0,0001). Fluoroscopy time was 17±7 min in the X-ray group vs. 18±6 min in the 3D group, respectively (p=ns). Fluoroscopy dose was 5,1±4,8 Gy.cm2 in the X-ray group vs. 5,6±4,7 Gy.cm2 in the 3D group (p=ns). Acute PVI rate was 100% in both groups. There were no phrenic nerve palsies or esophageal complications. Major complications (2,1%) were pericardial tamponade (1,6%) and stroke (0,47%); one stroke resulted in death (0,23%). They occurred in 1,9% of patients in the X-ray group (4 pericardial tamponades, 2 strokes) vs. 2,8% in the 3D group (2 pericardial tamponades), respectively (p=ns). Minor complications (0,7%) were vascular. More than 75% of the major complications occurred in the first tertile of the treated patients. All tamponades occured when using a straight-tip, extrastiff guide wire for the over-the-wire PFA catheter. After changing to a J-tip guide wire, no tamponades occurred anymore.

Conclusions:

In a large, single center cohort of unselected patients, PVI using PFA with or without 3D mapping system resulted in a similar acute outcome and safety profile. Procedure and fluoroscopy times were significantly shorter in the fluoroscopy only group. There were no PFA-specific complications. The majority of complications occurred in the first tertile of treated patients. This may be explained by the learning curve of this new ablation technology and the use of a straight-tip, extrastiff guide wire for the over-the-wire PFA catheter.