First-in-Human Experience and Acute Procedural Outcomes Using a Novel Pulsed Field Ablation System: The PULSED AF Pilot Trial

Abstract

Background: Pulsed field ablation (PFA) is a novel form of ablation using electrical fields to ablate cardiac tissue. There are only limited data assessing the feasibility and safety of this type of ablation in humans.

Methods: PULSED AF (Pulsed Field Ablation to Irreversibly Electroporate Tissue and Treat AF; https://www.clinicaltrials.gov; unique identifier: NCT04198701) is a nonrandomized, prospective, multicenter, global, premarket clinical study. The first-in-human pilot phase evaluated the feasibility and efficacy of pulmonary vein isolation using a novel PFA system delivering bipolar, biphasic electrical fields through a circular multielectrode array catheter (PulseSelect; Medtronic, Inc). Thirty-eight patients with paroxysmal or persistent atrial fibrillation were treated in 6 centers in Australia, Canada, the United States, and the Netherlands. The primary outcomes were ability to achieve acute pulmonary vein isolation intraprocedurally and safety at 30 days.

Results: Acute electrical isolation was achieved in 100% of pulmonary veins (n=152) in the 38 patients. Skin-to-skin procedure time was 160±91 minutes, left atrial dwell time was 82±35 minutes, and fluoroscopy time was 28±9 minutes. No serious adverse events related to the PFA system occurred in the 30-day follow-up including phrenic nerve injury, esophageal injury, stroke, or death.

Conclusions: In this first-in-human clinical study, 100% pulmonary vein isolation was achieved using only PFA with no PFA system-related serious adverse events. Graphic Abstract: A graphic abstract is available for this article.

Keywords: atrial fibrillation; catheter ablation; electroporation; follow-up studies.

Figure 1.

Pulsed field ablation delivered to a 9-gold circular electrode array (electrode length, 3 mm; 20° forward tilted array with diameter of 25 mm; 9F shaft) in a biphasic, bipolar configuration generates an electric field confined to the area immediately surrounding the array.

Figure 2.

Isolation of pulmonary veins with pulsed field ablation. Pulmonary vein potentials recorded from bipolar electrograms from the nine-gold electrode array are shown immediately before and after PFA delivery in the left inferior (A), left superior (B), right inferior (C), and the right superior (D) pulmonary veins demonstrating efficient electrical PV isolation.

Figure 3.

Evidence of pulmonary vein block recorded from bipolar electrograms from the 9-gold electrode array. In (A), we see exit block demonstrated by pacing within the left superior pulmonary vein with no conduction to the rest of the atrium (green coronary sinus signals). In (B), after one pulsed field application, we see delay in the pulmonary vein potential compared with preablation (white arrow). In (C), we see further delay in the pulmonary vein potential after one more application of pulsed field ablation (white arrow) and then pulmonary vein block (asterix).

Figure 4.

Postablation voltage maps of patients treated with pulsed field ablation. A demonstrates how the catheter electrode array position was tracked on a subset of cases using an electroanatomical mapping system. The catheter positionings were overlaid on the preablation voltage map (A, left) and on the postablation voltage map (A, right). At least 4 catheter positions were required around each pulmonary vein (PV) to achieve full ostial and antral PV isolation, as demonstrated in another patient (B).