Overview of the Food and Drug Administration Circulatory System Devices Panel Meetings on WATCHMAN Left Atrial Appendage Closure Therapy

The WATCHMAN left atrial appendage closure (LAAC) technology is a percutaneously delivered permanent cardiac implant placed in the LAA. This device is designed to reduce the risk of stroke and systemic embolism in warfarin-eligible patients with nonvalvular atrial fibrillation. The first circulatory system device panel reviewed the Embolic Protection in Patients With Atrial Fibrillation (PROTECT AF) study in 2009, and a “not approvable” letter was issued by the US Food and Drug Administration (FDA) based on safety concerns. Subsequently, the FDA, collaboratively with the sponsor, designed a new Prospective Randomized Evaluation of the WATCHMAN LAAC Device in Patients With Atrial Fibrillation Versus Long-Term Warfarin Therapy (PREVAIL) trial to address the earlier study limitations. A second panel was convened in December 2013 to review the results of PREVAIL and additional long-term follow-up data from PROTECT AF. The second panel voted favorably 13 to 1 that the benefits of the WATCHMAN LAAC therapy do outweigh the risks for use in patients who meet the criteria specified in the proposed indication. Subsequently, and during the premarket approval review, updated data from the PREVIAL study revealed more ischemic strokes in the WATCHMAN group, corresponding to a total of 13 ischemic strokes in the WATCHMAN group versus 1 in the control group. As a result of these strokes, the FDA called for a third panel to assess the benefit-risk profile of the WATCHMAN device. This summary aims to describe the discussions and recommendations made during the panel meetings.