Boston Scientific Presents Clinical Data on Two Therapies for Atrial Fibrillation

Boston Scientific Corporation announced data supporting the use of the FARAPULSE Pulsed Field Ablation (PFA) System and the WATCHMAN FLX Left Atrial Appendage Closure (LAAC) Device, respectively, during a late-breaking science session at AF Symposium 2025.

ADVANTAGE AF Clinical Study

The ADVANTAGE AF study examined the use of the FARAPULSE PFA System for both PVI and posterior wall ablation (PWA) in patients who have persistent AF, where individuals experience an irregular or rapid heartbeat that lasts longer than seven days and which represent 25% of all AF cases.¹

The FARAPULSE PFA System is approved for pulmonary vein isolation (PVI) in patients who have paroxysmal AF, an irregular heartbeat that occurs occasionally and typically spontaneously resolves back to normal rhythm.

The prospective, single-arm trial included 260 patients enrolled at 43 global sites who were drug intolerant to at least one Class I/III anti-arrhythmic drug (AAD).

Key findings from the first 12 months include:

• The primary effectiveness endpoint – defined as freedom from AF, atrial flutter, atrial tachycardia, re-ablation, cardioversion, and use of a new or escalated dose of Class I/III AAD or amiodarone – was met at 63.5%.
• The primary safety endpoint – defined as serious adverse events related to either the use of an ablation catheter or the ablation procedure within seven days of the primary procedure and pulmonary vein stenosis or atrio-esophageal fistula out to 12 months – was met with a 2.3% event rate.
• The symptomatic AF recurrence-free rate was 85.3% and observationally, among physicians who performed three or more procedures, the symptomatic recurrence-free rate increased to 91.8%.
• There were no reported incidences of stroke, pulmonary vein stenosis, atrio-esophageal fistula, or major access complications.

OPTION Trial Sub-Analysis

The late-breaking session also included a prespecified sub-analysis from the OPTION clinical trial that built upon the positive primary endpoint results presented at the American Heart Association 2024 meeting. The results were also published in The New England Journal of Medicine.²

In line with the overall 36-month outcomes from this first head-to-head study of the WATCHMAN FLX device and direct oral anticoagulants (95% DOAC, 5% warfarin), the sub-analysis of 1,600 patients with atrial fibrillation who underwent device implantation either concomitantly or sequentially (90-180 days post ablation) demonstrated:

• Consistent with the previously presented primary safety and efficacy endpoint data presented in November 2024, concomitant LAAC with the WATCHMAN FLX device following an ablation demonstrated a statistically significant 44% reduction in non-procedural bleeding outcomes compared to OAC at 36 months (8.0% vs. 13.3%; p=0.02) and similar efficacy outcomes (7.0% vs. 6.7% p=0.91), with the primary efficacy endpoint defined as all-cause death, stroke or systemic embolism.
• Consistent with the previously presented primary safety and efficacy endpoint data, sequential LAAC with the WATCHMAN FLX device following an ablation demonstrated a statistically significant 62% reduction in non-procedural bleeding outcomes compared to OAC at 36 months (8.8% vs. 21.5%; p<0.0001) and similar efficacy outcomes (4.2% vs. 5.3%; p=0.45).
• Similar stroke protection with the WATCHMAN FLX device compared to OAC irrespective of concomitant (2.3% vs. 2.5% rates of all strokes) or sequential (1.1% vs 1.6%) implantation.

References:

¹ Zoni-Berisso M, Lercari F, Carazza T, Domenicucci S. Epidemiology of atrial fibrillation: European perspective. Clin Epidemiol. 2014;6:213-220. doi: 10.2147/CLEP.S47385

² Wazni OM, Saliba WI, Nair DG, et al. Left atrial appendage closure after ablation for atrial fibrillation. N Engl J Med. 2024 Nov 16. doi:10.1056/NEJMoa2408308