Positive three-year primary endpoint results from the OPTION global clinical trial of the Watchman FLX Left Atrial Appendage Closure (LAAC) Device. - Boston Scientific

Key findings from the study comparing the device to first-line oral anticoagulation (OAC) – including direct oral anticoagulants (DOAC) (95%) and warfarin (5%) – for stroke risk reduction in patients with non-valvular atrial fibrillation following a cardiac ablation were presented in a late-breaking science session at the American Heart Association's Scientific Sessions 2024, and simultaneously published in The New England Journal of Medicine.

The trial met the primary safety endpoint of non-procedural major bleeding or clinically relevant non-major bleeding at 36 months, with the Watchman FLX device demonstrating superiority to OAC (8.5% vs.18.1%; P<0.0001). It also met the primary efficacy endpoint of all-cause death, stroke or systemic embolism at 36 months, with the data showing non-inferiority of the device to OAC (5.4% vs. 5.8%; P<0.0001). Additional findings included non-inferiority of the Watchman FLX device for the combined secondary endpoint of procedural and non-procedural major bleeding at 36 months (3.9% vs. 5.0%; P<0.0001).

In recent years, the number of patients with atrial fibrillation who have undergone a cardiac ablation procedure to prevent symptoms has grown significantly. Due to the risk of atrial fibrillation recurrence following an ablation, current treatment guidelines recommend that patients with multiple stroke risk factors remain on OAC long term to reduce the risk of stroke. However, symptomatic relief can lead these patients to stop taking their blood thinners, increasing this risk, while long-term use of OAC also presents a risk of serious bleeding.

"The OPTION trial data provide clinical evidence indicating that, among patients who have undergone an ablation, LAAC with the Watchman FLX  device is not only as safe, but superior to OAC therapy for reducing the risk of long-term bleeding events," said Dr. Oussama Wazni, vice chairman of Cardiovascular Medicine and section head, Cardiac Electrophysiology, Cleveland Clinic, and principal investigator of the OPTION trial.* "Notably, we found high rates of procedural success in patients who had a Watchman FLX implant after an ablation, and of patient adherence to their prescribed medication regimen following the procedures, which likely reinforced positive outcomes such as the low rates of ischemic and hemorrhagic stroke within the trial population."

The randomized, controlled OPTION trial included 1,600 patients enrolled across 114 sites in the United States, Europe and Australia, and demonstrated high rates of procedural success. In the trial, approximately 60% of device patients had their Watchman FLX  implant 90-180 days following their ablation procedure. The other nearly 40% of the device patients had the two procedures performed concomitantly, with the Watchman FLX implant taking place after the ablation.

"The OPTION trial is the first large, randomized trial to rigorously evaluate LAAC as a safe and effective stroke risk reduction treatment following a cardiac ablation in a head-to-head fashion against commonly used oral anticoagulants, including DOAC," said Brad Sutton, M.D., chief medical officer, Atrial Fibrillation Solutions, Boston Scientific. "These positive primary outcomes mean that patients receiving the Watchman FLX device were able to eliminate long-term medication use while maintaining stroke protection. With this data, we see potential to both expand the indication for the Watchman FLX  platform and ultimately elevate it to become a frontline therapy for patients receiving cardiac ablation for atrial fibrillation to reduce their risk of stroke."

In addition to the OPTION trial, the Watchman  technology is being evaluated against DOAC as a first-line therapy in lower-risk patients within the CHAMPION-AF randomized trial. The latest-generation Watchman  Pro LAAC Device, which was approved in the United States in 2023, is similarly being studied in several clinical trials, including the SIMPLAAFY randomized controlled trial that is evaluating a single-drug alternative to dual anti-platelet therapy as a post-procedural regimen.

Citation :"Left Atrial Appendage Closure after Ablation for Atrial Fibrillation"; Oussama M. Wazni, M.D., Walid I. Saliba, M.D., Devi G. Nair, M.D., Eloi Marijon, M.D., Ph.D., Boris Schmidt, M.D., Troy Hounshell, D.O., Henning Ebelt, M.D., +22, for the OPTION Trial Investigators^*.Published November 16, 2024. DOI: 10.1056/NEJMoa2408308