An FDA advisory committee is scheduled to vote Oct. 8 on the Watchman Left Atrial Appendage Closure device to reduce the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. The FDA asked panelists to re-evaluate the filing in light of new clinical data on adverse events.
Four-year results of PROTECT AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients with Atrial Fibrillation) presented at the Heart Rhythm Society scientific session in 2013 showed Watchman to be superior to warfarin for primary efficacy and mortality. The multicenter, prospective randomized clinical trial assessed the safety and efficacy of the Watchman device (Boston Scientific), which is designed to close off the left atrial appendage, where blood can pool and form clots.
Also in 2013, another Watchman trial—PREVAIL (Watchman LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy)—was yanked as a late-breaking clinical trial because the sponsor broke an embargo by announcing the study met two of its three primary endpoints. There was a reduction in hemorrhagic stroke compared with warfarin but an increase in perioperative events.
In December 2013, the Circulatory System Devices Panel voted 13-1 in favor of Watchman after a review of the two clinical trials. The FDA placed the premarket approval application on the panel’s agenda again in 2014 for “review and recommendations regarding new clinical data and associated additional adverse events including stroke that have become available since the previous advisory committee meeting.”
The Watchman is proposed for use in patients with nonvalvular atrial fibrillation who are eligible for warfarin therapy to reduce the risk of stroke and systemic embolism. The device is approved in Europe and some parts of Asia.
The panel also will vote on the safety, effectiveness and classification of more-than-minimally manipulated allograft heart valves.