FDA Finally Approves Watchman Device from Boston Scientific

Boston Scientific Corp. received U.S. Food and Drug Administration (FDA) approval for its Watchman Left Atrial Appendage Closure Device. According to the company, Watchman offers a new stroke risk reduction option for high-risk patients with non-valvular atrial fibrillation (AF) who need an alternative to long-term therapy with warfarin (a commonly prescribed blood thinner). The approval is a big win for Boston Scientific, which has been working to gain U.S. approval to sell watchman for more than six years.

The device will be made available to U.S. centers involved in the company’s clinical studies and additional, specialized centers as physicians are trained on the implant procedure, Boston Scientific officials said.

Watchman has been commercially available internationally since 2009. Boston Scientific officials estimate that the global market for Watchman is about $500 million annually. Some analysts and physicians, however, have argued that adoption of the device could be limited because of newer treatment options that have emerged since Watchman was first submitted for approval in 2008.

The device has bee declined by the FDA twice before as a result safety and efficacy concerns. The agency held three advisory committee meetings of outside experts to evaluate Watchman between 2009 and 2014. At the most recent meeting in October, Watchman was shown to be inferior to warfarin in preventing the most common type of stroke caused by blood clots. The committee, however, narrowly voted to recommend the device for approval, citing the need to treat patients who are ineligible for warfarin or refuse to take it.

Non-valvular atrial fibrillation is an irregular heartbeat that can lead to blood clots, stroke, heart failure and other heart-related complications.  AF is the most common cardiac arrhythmia, currently affecting more than 5 million Americans, according to figures cited by Boston Scientific. Patients with AF have a five-fold increased risk of stroke due to blood stagnating from the improperly beating atrium and the resulting blood clot formation. Twenty percent of all strokes occur in patients with AF. Stroke is more severe for patients with AF, as they have a 70 percent chance of death or permanent disability.

The most common treatment for stroke risk reduction in patients with AF is blood-thinning warfarin therapy.  Despite its proven efficacy, long-term warfarin therapy is not well-tolerated by some patients due to numerous quality-of-life tradeoffs such as dietary restrictions and regular blood monitoring, and carries a significant risk for bleeding complications. 

Watchman is a catheter-delivered heart implant designed to close the left atrial appendage (LAA) in order to prevent the migration of blood clots from the LAA, and thus, reduce the incidence of stroke and systemic embolism for higher-risk patients with non-valvular AF.  The LAA is a thin, sack-like appendix arising from the heart and is believed to be the source of more than 90 percent of stroke-causing clots that come from the left atrium in patients with non-valvular AF.

Watchman is indicated to reduce the risk of thromboembolism from the left atrial appendage in patients with non-valvular atrial fibrillation who are at increased risk for stroke and systemic embolism based on CHADS2 or CHA2DS2-VASc scores, are deemed by their physicians to be suitable for warfarin; and have an appropriate rationale to seek a non-pharmacologic alternative to warfarin, taking into account the safety and effectiveness of the device compared to warfarin.

“The Watchman device is an important step forward in stroke management for patients with AF,” said Vivek Reddy, M.D., director of the Cardiac Arrhythmia Service at the Mount Sinai Medical Center and co-principal investigator of the PROTECT AF and PREVAIL studies. “We know that up to 40 percent of patients who are eligible for oral anticoagulation do not take it for numerous reasons1, highlighting the need for additional treatment options. The watchman device is a breakthrough treatment providing those patients who are suitable for warfarin with an implant-based alternative to long-term warfarin therapy while still reducing the risk of stroke.” 

The FDA approval is based on a clinical program that consists of more than 2,400 patients and nearly 6,000 patient-years of follow-up. The clinical program provided strong evidence that the Watchman device can be implanted safely and reduces the risk of stroke in eligible patients while enabling most patients to discontinue warfarin. Additionally, a meta-analysis of all of the randomized trial data demonstrated that while ischemic stroke reduction favored warfarin, Watchman provided patients with a comparable protection against all-cause stroke and statistically superior reductions in hemorrhagic stroke, disabling stroke, and cardiovascular death compared to warfarin over long-term follow-up, according to the company.

“Today marks a defining moment in the company’s journey towards establishing left atrial appendage closure therapy in the United States.  Boston Scientific is proud to offer this potentially life-changing stroke risk treatment option to high-risk patients with AF who have a reason to seek a non-drug alternative to warfarin.   This therapy could free them from the challenges of long-term warfarin therapy,” said Joe Fitzgerald, executive vice president and president, Rhythm Management, Boston Scientific.  “FDA approval of the Watchman device is another example of Boston Scientific delivering on its commitment to bring meaningful innovations to patient care.”

Boston Scientific is based in Marlborough, Mass.  The company’s stock value increased following FDA approval of the device.