CHAMPION-AF study of the WATCHMAN FLX™ Left Atrial Appendage Closure Device as a first-line therapy for stroke risk reduction meets all primary and secondary safety and efficacy endpoints
Data highlights the WATCHMAN FLX device provided statistically superior protection from bleeding, demonstrated similar efficacy compared to blood thinners in patients with non-valvular atrial fibrillation
Late-breaking findings presented at ACC.26 and simultaneously published in The New England Journal of Medicine
MARLBOROUGH, Mass. and NEW ORLEANS, March 28, 2026 /PRNewswire/ -- Boston Scientific Corporation (NYSE: BSX) today announced that the CHAMPION-AF global clinical trial met all primary and secondary safety and efficacy endpoints. The study evaluated the WATCHMAN FLX™ Left Atrial Appendage Closure (LAAC) Device compared to non-vitamin K antagonist oral anticoagulants (NOACs) as a first-line option for stroke risk reduction in a broad population of patients with non-valvular atrial fibrillation (NVAF). Key results were presented as a late-breaking clinical trial at the American College of Cardiology's Annual Scientific Session & Expo and simultaneously published in The New England Journal of Medicine.
Atrial fibrillation (AF) is an increasingly common heart rhythm disorder that affects approximately 59 million people worldwide1 and increases stroke risk by five times compared to people with a normal heart rhythm.2 In patients with NVAF, more than 90% of heart-related blood clots form in the left atrial appendage (LAA).3 An alternative to long-term NOACs – considered the leading contemporary blood thinners for stroke risk reduction in patients with NVAF – the WATCHMAN technology is designed to permanently close off the LAA and is implanted in a single procedure.
"The success of the landmark CHAMPION-AF trial represents a meaningful milestone that will undoubtedly transform the treatment approach to stroke risk reduction in a broader population of patients who historically have needed to rely on medication," said Martin Leon, M.D., study co-chair and Mallah Family professor of cardiology, chief innovation officer and director, Cardiovascular Data Science Center, Columbia University Medical Center.* "These results should give clinicians confidence in the potential of the WATCHMAN FLX device to become a first-line treatment option for reducing the risk of stroke for a rapidly growing number of patients with AF."
The randomized, controlled trial enrolled 3,000 patients with NVAF who were suitable for oral anticoagulation therapy across a broad spectrum of stroke and bleeding risk. At 36 months:
- The primary safety endpoint was met with data demonstrating the WATCHMAN FLX device was statistically superior to NOACs (10.9% vs. 19.0%; P
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