What is the Watchman (Left Atrial Appendage Closure) device?

From the Guidelines

The Watchman device is a percutaneous left atrial appendage (LAA) occlusion device that provides an alternative to long-term oral anticoagulation for stroke prevention in patients with atrial fibrillation who are at increased risk of stroke and are poor candidates for long-term oral anticoagulation. The device has been compared with warfarin in patients with AF in two randomized controlled trials (RCTs): the PROTECT AF and PREVAIL trials, which demonstrated that patients receiving the device had significantly fewer hemorrhagic strokes than those receiving warfarin, but with an increase in ischemic strokes in the device group 1. However, when periprocedural events were excluded, the difference in ischemic strokes was not significant.

Key Points About the Watchman Device

• It is inserted into the left atrial appendage of the heart through a minimally invasive procedure to permanently close off the area where blood clots often form in patients with atrial fibrillation.
• The procedure typically takes about an hour under general anesthesia, with patients usually staying in the hospital overnight and returning to normal activities within a few days.
• After implantation, patients take blood thinners for a period of time while heart tissue grows over the device, followed by dual antiplatelet therapy and eventually aspirin alone indefinitely.
• The Watchman device is particularly beneficial for patients who have a high risk of bleeding complications from long-term anticoagulation therapy, providing an alternative way to manage stroke risk without the need for lifelong blood thinners.

Patient Selection and Indications

• The Centers for Medicare & Medicaid Services (CMS) specifies that patients should have a CHADS2 score ≥2 or a CHA2DS2-VASc score ≥3 to be considered for the device.
• The device is an option for patients who are suitable for short-term warfarin but deemed unable to take long-term oral anticoagulation.
• Important differences in wording between the FDA approval and CMS approval should be considered when selecting patients for the Watchman device, with the FDA approval restricting the device to patients who are deemed suitable for long-term warfarin but have an appropriate rationale to seek a nonpharmacological alternative 1.

From the Research

Overview of the Watchman Device

• The Watchman device is a left atrial appendage closure device used to prevent stroke in patients with atrial fibrillation 2, 3, 4, 5, 6.
• It is a non-pharmacologic alternative to oral anticoagulants (OACs) and direct oral anticoagulants (DOACs) for patients with atrial fibrillation who are at increased risk for stroke or systemic embolism 5.

Mechanism of Action

• The Watchman device permanently seals off the left atrial appendage (LAA) to prevent thrombi from escaping into the circulation 4, 5.
• The device is implanted through a transseptal cannula inserted through the femoral vein, and under fluoroscopic guidance, the inter-atrial septum is crossed 4.

Indications and Patient Selection

• The Watchman device is indicated for patients with atrial fibrillation who are at increased risk for stroke or systemic embolism and have contraindications to OACs or DOACs 2, 3, 6.
• Patients with a CHA2DS2-VASc score ≥2 (men) or ≥3 (women) are eligible for the device 5.

Clinical Trials and Efficacy

• The Watchman device has been shown to be non-inferior to warfarin for the prevention of stroke and systemic embolization related to non-valvular atrial fibrillation (NVAF) 2.
• The CHAMPION-AF trial is ongoing to compare the efficacy and safety of the Watchman FLX device to DOACs in patients with atrial fibrillation 5.
• The device has been shown to reduce the risk of stroke in patients with atrial fibrillation, and its implantation is considered safe and feasible 3, 4.

Complications and Risks

• Procedure-related complications include pericardial effusion, device embolization, procedure-related ischemic stroke, and device-related thrombosis (DRT) formation 2.
• Post-implantation therapy should be optimized according to individual patient bleeding risk, DRT formation, and contraindication to DOACs 2.