Boston Scientific's Watchman FLX device has demonstrated superiority to oral anticoagulants (OAC) in reducing bleeding events in patients with non-valvular atrial fibrillation who have undergone cardiac ablation. The results of the OPTION trial, presented at the American Heart Association's Scientific Sessions 2024 and published in The New England Journal of Medicine, indicate that Watchman FLX offers a safer alternative for stroke risk reduction in this patient population.
The OPTION trial, a randomized, controlled study involving 1,600 patients across 114 sites in the U.S., Europe, and Australia, compared Watchman FLX to first-line OAC, including direct oral anticoagulants (DOAC) (95%) and warfarin (5%). The primary safety endpoint was non-procedural major bleeding or clinically relevant non-major bleeding at 36 months. The primary efficacy endpoint was all-cause death, stroke, or systemic embolism at 36 months.
Superiority in Bleeding Reduction
The trial met its primary safety endpoint, with Watchman FLX demonstrating superiority to OAC in reducing bleeding events. Specifically, Watchman FLX produced an 8.5% rate of clinically relevant non-major bleeding, compared to 18.1% in the OAC arm. This significant reduction in bleeding events highlights a key advantage of the Watchman FLX device, particularly for patients at higher risk of bleeding complications with long-term anticoagulant use.
Non-Inferiority in Stroke Prevention
For the primary efficacy endpoint of all-cause death, stroke, or systemic embolism, the rate was 5.4% for Watchman FLX and 5.8% for OAC, demonstrating non-inferiority. Additionally, procedural and non-procedural major bleeding rates were 3.9% for Watchman FLX and 5% for OAC.
Expert Commentary
"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 chair of Cardiovascular Medicine and section head, Cardiac Electrophysiology, Cleveland Clinic, and principal investigator of the OPTION trial. He also noted the high rates of procedural success and patient adherence to medication regimens, which likely contributed to the positive outcomes.
Implications for Clinical Practice
These findings suggest that Watchman FLX could become a frontline therapy for stroke risk reduction in patients with atrial fibrillation undergoing cardiac ablation. By eliminating the need for long-term oral anticoagulation, Watchman FLX offers a potential solution to reduce bleeding risks and improve patient outcomes. Boston Scientific anticipates an FDA label expansion in the second half of 2025 based on these data.
Ongoing Research
Boston Scientific is also conducting the CHAMPION-AF trial, evaluating Watchman against DOAC as a first-line therapy in lower-risk patients. Additionally, clinical trials are underway to assess the latest-generation Watchman FLX Pro, which received FDA approval in September 2023. The SIMPLAAFY trial is examining a single-drug alternative to dual anti-platelet therapy as a post-procedural regimen for Watchman FLX Pro.
