After reviewing updated data and analysis for the Boston Scientific Corporation Watchman Left Atrial Appendage Closure (LAAC) Device, the US Food and Drug Administration (US FDA) Circulatory System Devices Panel of the Medical Devices Advisory Committee voted in favour of the device. By a vote of 6 to 5 (with 1 abstention) the Panel concluded that the benefits of the Watchman Device outweigh the potential risks.  

Furthermore, the Panel voted that there is reasonable assurance that the Device is safe (12 yes to 0 no). On the question of reasonable assurance of effectiveness, the Panel vote was unfavourable (6 yes to 7 no).  The Panel provided substantial input and guidance related to the proposed Indications for Use and target patient population. There was widespread agreement among the Panel members that the Device provides a much needed alternative to long-term anticoagulation for some patients. While not bound by this vote, the FDA takes advisory panel comments and recommendations into account when reviewing the Watchman device application. The company is committed to working with the FDA to address the Panel's comments.  

"There is a strong clinical need for a proven device alternative to long-term warfarin therapy for my high stroke risk patients with non-valvular atrial fibrillation," said Vivek Reddy, M.D., Director of the Cardiac Arrhythmia Service at Mount Sinai Medical Center and co-principal investigator of the PROTECT AF and PREVAIL studies.  "I'm encouraged that the Panel recognised the importance of having the Watchman Device as an option for appropriate patients."

The Committee's positive vote followed a review of the most recent clinical data and analysis from two randomised control trials, PROTECT AF and PREVAIL, as well as from the CAP (Continued Access Protocol) and CAP2 registries. The Watchman Device is the most studied left atrial appendage closure device and the only one with long-term clinical data from over 2,400 patients and nearly 6,000 patient-years of follow-up in clinical studies.  The Watchman Device was approved for sale in Europe in 2005 and is currently approved in more than 70 countries across the globe. In the US, the Watchman Device is an investigational device, limited to investigational use and not available for sale.      

"Today's recommendation by the Panel is another step toward making this innovative technology available to high risk patients with non-valvular atrial fibrillation who are eligible for warfarin, but who have reasons to seek an alternative to long-term therapy," said Kenneth Stein, M.D., chief medical officer, rhythm management, Boston Scientific. "We continue to believe that the totality of the data for the Watchman Device provide reasonable assurance of its safety and efficacy as a treatment alternative for these patients. We look forward to our ongoing discussions with FDA."

Atrial fibrillation (AF) 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 five million Americans. 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 seventy per cent chance of death or permanent disability.

The most common treatment to reduce the risk of stroke prevention in patients with AF is anticoagulant ("blood-thinning") therapy with warfarin.  Despite its proven efficacy, long-term warfarin therapy may be poorly tolerated by some patients and carries a significant risk for bleeding complications.

The Watchman Device 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 a majority of stroke-causing blood clots in people with AF. The Watchman Device is commercially approved in more than 70 countries, with more than 9,000 implants performed worldwide.  The device was developed by Atritech, which Boston Scientific acquired in March 2011.