Boston Scientific Announces CHAMPION-AF Trial Success: WATCHMAN FLX™ Device Meets All Endpoints as Potential First-Line Stroke Risk Reduction Option
Boston Scientific Corporation has announced that its 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 as a first-line option for stroke risk reduction in patients with non-valvular atrial fibrillation (NVAF), comparing it to non-vitamin K antagonist oral anticoagulants (NOACs).
The CHAMPION-AF global clinical trial successfully met all primary and secondary safety and efficacy endpoints, positioning the WATCHMAN FLX™ device as a potential first-line treatment for stroke risk reduction in patients with non-valvular atrial fibrillation (NVAF).
Key Findings
The compelling results of the trial were presented at ACC.26 and simultaneously published in The New England Journal of Medicine.
Atrial fibrillation (AF) is a common heart rhythm disorder, affecting approximately 59 million people worldwide, and significantly increases stroke risk. For patients with NVAF, more than 90% of heart-related blood clots form in the left atrial appendage (LAA). The innovative WATCHMAN technology is designed to permanently close the LAA in a single procedure, providing a crucial alternative to long-term non-vitamin K antagonist oral anticoagulants (NOACs).
Trial Overview
The CHAMPION-AF trial was a robust, randomized, controlled study. It successfully enrolled 3,000 patients with NVAF who were suitable for oral anticoagulation therapy. The extensive trial involved 141 sites across the U.S., Canada, Europe, Japan, and Australia, achieving an impressive 99% procedural success rate for device implantation.
Detailed Results at 36 Months
At 36 months, the study reported the following significant outcomes:
- Primary Safety Endpoint: The WATCHMAN FLX device demonstrated statistical superiority to NOACs for non-procedural major and clinically relevant non-major bleeding (10.9% vs. 19.0%; P<0.001), achieving a 45% relative reduction in non-procedural bleeding risk. When including procedural bleeding in a secondary analysis, the device still showed a significant reduction in bleeding compared to NOACs (12.8% vs. 19.0%; P<0.001), representing a 34% relative reduction in overall bleeding risk.
- Primary Efficacy Endpoint: The WATCHMAN FLX device achieved statistical non-inferiority compared to NOACs for the occurrence of stroke, cardiovascular or unexplained death, or systemic embolism (5.7% vs. 4.8%; P<0.001).
- Secondary Safety Endpoint: The device was statistically non-inferior to NOACs for procedural and non-procedural major bleeding (5.9% vs. 6.4%; P<0.001).
- Secondary Combined Safety and Efficacy Endpoint: The device demonstrated statistical superiority to NOACs for the occurrence of cardiovascular death, stroke, systemic embolism, and non-procedural major and clinically relevant non-major bleeding (15.1% vs. 21.8%; P<0.001).
Implications
"This trial’s success represents a significant milestone that could profoundly influence the treatment approach for stroke risk reduction in a broader patient population," noted Dr. Martin Leon, study co-chair. "These results may provide clinicians with confidence in the WATCHMAN FLX device as a potential first-line treatment option."
Brad Sutton, M.D., chief medical officer at Atrial Fibrillation Solutions, Boston Scientific, stated that these compelling data could support updated clinical guidelines globally. The company plans to leverage these findings in submissions to expand the indication and coverage for the WATCHMAN platform as a first-line stroke risk reduction option. Dr. Sutton highlighted a critical challenge: "40% of AF patients prescribed blood thinners for stroke risk reduction do not take their medications consistently, which significantly increases their stroke risk." He emphasized that the WATCHMAN device offers a unique solution: "a one-time implant for durable stroke risk protection."
The WATCHMAN implant stands as the most implanted and studied LAAC device on the market, having been successfully used in over 600,000 patients worldwide. The device was initially introduced in Europe in 2009 and subsequently approved by the U.S. Food and Drug Administration (FDA) in 2015. Patient follow-up for the CHAMPION-AF trial is set to continue through five years, providing further long-term data.