U.S. — The STUN-AF study indicated that pulsed field ablation (PFA) of the left atrial appendage (LAA) reduced peridevice leaks in patients undergoing concomitant atrial fibrillation ablation and LAA closure. Patients who received PFA on the LAA showed a higher rate of no peridevice leaks on imaging at both 4 and 12 months after the procedure, compared to those who did not.

At 4 months, 71% of patients with LAA PFA had no peridevice leaks, while 36% of those without LAA PFA had no leaks (P<0.001). This difference increased by 12 months, with 96% of the PFA group having no peridevice leaks compared to 58% in the non-PFA group (P<0.001). The study also found that ablation of the LAA reduced peridevice leaks and correlated with lower LAA emptying velocities.

Vivek Reddy, MD, from Mount Sinai Fuster Heart Hospital, stated, "The physiological conclusion is that residual contractility is a modifiable contributor to an incomplete appendage seal." He added, "Consider this in patients undergoing concomitant ablation." Dr. Reddy presented these findings at the New York Valves annual meeting hosted by the Cardiovascular Research Foundation.

Peridevice leaks are associated with an increased risk of ischemic strokes and other thrombotic events following LAA occlusion. LAA occlusion is used to prevent strokes in atrial fibrillation patients who have a high bleeding risk for long-term anticoagulation therapy. Puvi Seshiah, MD, from the Christ Hospital in Cincinnati, commented, "It's sort of sobering that only about 50% of left atrial appendage devices actually have complete closure now. This is going to become important because we are starting to recommend left atrial appendage occlusion as an [alternative] option to medical therapy, so this is a first step in the direction of trying to address and improve peridevice closure."

The STUN-AF study was an observational cohort study that included 327 individuals across three U.S. centers. The cohort had a mean age of 76, comprised 58% men, and 55% had paroxysmal atrial fibrillation. The average CHA2DS2-VASc score for the cohort was 4.3. The most common indications for LAA closure in the study were bleeding at 41% and falls at 32%. PFA catheters used primarily included Farawave and Sphere-9, with a fewer number of patients undergoing PulseSelect and Varipulse PFA.

Patients who completed 12-month imaging included 83 who received LAA ablation and 43 who did not. However, Reddy noted, "Follow-up imaging modality did differ between participants. We didn't have 12-month imaging in all patients ... and of course we had insufficient patients to comment if this results in any change in clinical outcomes." He also commented, "We would certainly want to see a future prospective trial, and I think this has implications for future appendage device iterations. Ultimately, we do need a randomized trial."

Periprocedural adverse events associated with LAA ablation included transient ischemic attack in 0.5% of cases and bleeding in 1.4% of cases. During 3-month follow-up for the intervention group, major bleeds occurred in 2.3% of patients, myocardial infarction or coronary revascularization in 1.8%, and heart failure hospitalizations and deaths both occurred in 0.9% of patients. Stroke occurred in 0.5% of patients during this same follow-up period.