NEW YORK CITY — Physician Vivek Reddy presented findings from the STUN-AF study at the New York Valves annual meeting, indicating that applying pulsed field ablation (PFA) directly to the left atrial appendage (LAA) may improve sealing. The study observed a higher percentage of patients with no peridevice leaks after receiving LAA PFA compared to those who did not.

In the observational cohort study involving 327 individuals, 71% of patients who received PFA on the LAA had no peridevice leaks on imaging at 4 months, compared to 36% of those who did not. At 12 months, 96% of patients who underwent PFA on the LAA had no peridevice leaks, compared to 58% in the group that did not receive LAA PFA. The study was conducted at three U.S. centers.

Reddy, a physician at 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." Reddy also remarked on the need for future research, saying, "We would certainly want to see a future prospective trial, and I think this has implications for future appendage device iterations."

The cohort's mean age was 76, and 58% of the participants were men. Paroxysmal atrial fibrillation was noted in 55% of the cohort, and the average CHA2DS2-VASc score was 4.3. The most common reasons for LAA closure in this group were bleeding, accounting for 41% of cases, and falls, representing 32%.

The PFA catheters used in the study included a mix of Farawave and Sphere-9, with fewer patients undergoing PulseSelect and Varipulse PFA. Patients who reached 12-month imaging included 83 who received LAA ablation and 43 who did not. Reddy acknowledged some limitations of the study, noting, "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 emphasized, "Ultimately, we do need a randomized trial."

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

Peridevice leaks are associated with an increased risk of ischemic strokes and other thrombotic events following LAA occlusion. LAA occlusion is indicated for atrial fibrillation patients who are at a high bleeding risk for long-term anticoagulation therapy to prevent strokes. Puvi Seshiah, a physician at the Christ Hospital in Cincinnati, commented on the broader context of LAA occlusion, stating, "It's sort of sobering that only about 50% of left atrial appendage devices actually have complete closure now." Seshiah added, "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."