Two studies published in JACC: Clinical Electrophysiology on June 29 provide new insights on the durability of pulmonary vein isolation (PVI) with pulsed field ablation (PFA) vs. radiofrequency ablation (RFA) in patients with persistent atrial fibrillation (AFib), as well as the safety profile of PFA among patients undergoing their first ablation for AFib.

In a prospective, single-center study led by Oskar M. Galuszka, MD, et al., 30 patients with persistent AFib underwent RFA in phase 1 and 30 patients underwent PFA in phase 2. Of them, 51 agreed to undergo the mandated remapping procedure (26 in the RFA group and 25 in the PFA group). The mean age of the patients was 68 years and 12% were women.

Remapping occurred at a median of 7.2 months. The ablation procedure time was shorter with PFA than RFA (110 vs. 164 min; p<0.001), but fluoroscopy time was longer with PFA than RFA (17 vs. 6 min; p<0.001).

Results showed that with RFA and PFA, respectively, there was comparable durability of PVI at 76% (78/102 PVs) and 79% (82/104 PVs). Furthermore, after adjusting for remapping and left atrial volume, no difference was observed in the risk of PV reconnection between the two arms (adjusted odds ratio, 1.20; p=0.77). All PVs were durably isolated in 26 patients: 15 patients (58%) with RFA and 11 patients (44%) with PFA (p=0.406).

Looking at AFib recurrence, this was observed in nine of the 26 patients (35%) with completely isolated PVs before remapping and in seven of the 25 patients (28%) with reconnected PVs. At one year, 70% of patients were free of AFib recurrence following the redo procedure, with no difference between RFA and PFA (adjusted hazard ratio, 0.80; p=0.71).

"These observations suggest that in persistent [AFib], arrhythmia recurrence is not solely determined by PV reconnection but likely reflects a relevant contribution of non-PV mechanisms," write the authors.

Noting the high dropout rate and lack of randomization, Jason G. Andrade, MD, and Katherine C. Kulyk, DHA, write in an accompanying editorial comment that "the longer term multiple procedure success is difficult to interpret."

In a study using data from the DISRUPT AF registry, Elisabeth A. Wong, MD, et al., found that with pentaspline PFA there was a low rate of procedure/device-related adverse events (AEs), without injury to the esophagus, phrenic nerve and PVs.

The investigators identified 1,576 patients in the prospective registry who underwent first-time AFib ablation with PFA using the pentaspline catheter from April 2024 to May 2025 at 20 centers across the U.S. Their mean age was 68 years, 39% were women, and their mean body mass index was 31.5.

Results at three months showed AEs occurred in 2.2% of patients, with 1.6% classified as procedure/device related. The mortality rate was 0.3%. The most common AEs were vascular access complications (pseudoaneurysm 0.4%; hematoma 0.3%), pericarditis (0.2%) and other nonspecific events such as hypotension (0.4%).

Major procedure/device-related AEs occurred in 0.7% of patients, including stroke (0.3%), cardiac tamponade (0.1%), vascular injury requiring intervention (0.1%) and bleeding (0.1%), and there was one case (0.06%) of coronary vasospasm. No cases of esophageal injury, persistent phrenic nerve injury, PV stenosis or acute kidney injury were seen.

Of note, the rate of reported AEs decreased at the greatest level of operator experience regardless of procedural complexity.

"These findings enhance clinicians' understanding of the early safety characteristics of PFA in real-world practice and may inform procedural decision making when selecting ablation technologies for [AFib]," write the authors. "Future research should focus on randomized comparisons, durability of lesion formation, long-term clinical outcomes, and broader applicability across diverse patient populations and operator experience levels to facilitate informed adoption of PFA into routine clinical practice."