CMS approves Watchman study for patients with nonvalvular atrial fibrillation

CMS recentlyapproved a randomized study to assess the Watchman device (Boston Scientific) in patients unsuitable for oral anticoagulation.

The FDA approved the Watchman left atrial appendage (LAA) closure device in March 2015 for patients with nonvalvular atrial fibrillation. The device is intended to reduce the risk of stroke in patients who want an alternative to warfarin or oral anticoagulants.

The post-approval study, known as ASAP-TOO, plans on enrolling 888 adults age 18 or older who will be randomized in a 2:1 ratio to receive the Watchman device or receive treatment with zero or one antiplatelet medications.

All patients will have nonvalvular atrial fibrillation, be deemed unsuitable for oral anticoagulation and be deemed suitable to receive aspirin and clopidogrel following implantation with the Watchman device.

The primary safety endpoint is the seven-day combined rate of death, ischemic stroke, systemic embolism and complications requiring major cardiovascular or endovascular intervention, while the primary efficacy endpoint is the comparison of time to first event of ischemic stroke and systemic embolism.

Boston Scientific plans on completing the study by December 2023.

In February 2016, CMS released its final national coverage determination for percutaneous left atrial appendage closure for non-valvular atrial fibrillation. The rule made the Watchman device available to certain Medicare patients.

The American College of Cardiology has also launched a registry to track data on left atrial appendage occlusion devices. The registry serves as the FDA-mandated post-approval study for the Watchman device.