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CHAMPION-AF Clinical Trial


The CHAMPION-AF trial evaluates LAAC versus NOAC in a broad NVAF patient population to establish WATCHMAN FLXTM as a first-line stroke risk-reduction therapy. 

LAAC with WATCHMANTM or WATCHMAN FLX is currently used for patients who can tolerate short-term oral anticoagulation (OAC) therapy, but are considered poor candidates for long-term OAC.

However, there is a large population of low to moderate bleed risk patients* who can tolerate long term OAC, but would benefit from a one time, FDA-approved device alternative that offers a lifetime of safe and effective stroke risk reduction.

* Exclusion criteria includes patients who have had a prior major bleeding event in ISTH definition within the 30 days prior to randomization. Lack of resolution of related clinical sequelae or planned and pending interventions to resolve bleeding/bleeding source, are a further exclusion regardless of timing of the bleeding event.

Trial Design and Primary Endpoints

CHAMPION-AF Trial Design Endpoints

Primary Endpoints:

  • WATCHMAN FLX is non-inferior for the occurrence of stroke (including ischemic and/or hemorrhagic), cardiovascular (CV) death (including hemorrhagic and/or unexplained death), and systemic embolism at 36 months. 
  • WATCHMAN FLX is superior for non-procedural bleeding (ISTH major bleeding and clinically relevant non-major bleeding) at 36 months. 
  • WATCHMAN FLX is non-inferior for the occurrence of ischemic stroke and systemic embolism at 60 months.  

Trial Timeline

CHAMPION-AF is a randomized, controlled trial that will include 3,000 patients across 150 global sites. See below for an overview of both the device and control group treatment timelines.
WATCHMAN FLX LAAC Device Group Chart
NOAC Group Chart
NOTE: For Device and NOAC arms, annual clinical follow-up visits can be via phone or in-office, with the exception of the 3-year clinical follow-up visit, which must be in-office.

Patient Brochure

View the orderable patient-facing brochure created to give your trial candidates an overview of the CHAMPION-AF clinical trial.

Contact your WATCHMAN Representative to order patient brochures for your center.


Patient Selection

group of people smiling and looking happy
CHAMPION-AF intends to demonstrate WATCHMAN FLX as a first-line LAAC option versus NOAC to reduce stroke risk in NVAF patients, including lower-risk patients.
Find a Trial Site

Find a Trial Site

Boston Scientific has selected US sites to be CHAMPION-AF investigational centers. If you have a candidate in mind, view the active trial list provided by, and reach out to a study physician near you to discuss next steps for referral.

WATCHMAN FLX Device Brief Summary