What is the recommended antiplatelet and anticoagulant therapy after Watchman (Left Atrial Appendage Closure Device) implantation?

From the Guidelines

After a Watchman device implantation, the most recent and highest quality study recommends a regimen of warfarin (target INR 2.0-3.0) plus aspirin 81-100mg daily for 45 days post-procedure, followed by 6 months of dual antiplatelet therapy (aspirin plus clopidogrel), and then ongoing aspirin 81-100mg daily indefinitely 1. This approach is based on the latest guidelines and expert panel reports, which prioritize the prevention of device-related thrombus formation while minimizing bleeding risks associated with long-term anticoagulation. The use of warfarin and aspirin for the initial 45 days is crucial for preventing thromboembolic events, as evidenced by the PROTECT AF and PREVAIL AF trials 1. After 45 days, the transition to dual antiplatelet therapy with aspirin and clopidogrel helps to reduce the risk of bleeding while maintaining protection against thrombus formation. Some key points to consider in this regimen include:

• The importance of transesophageal echocardiogram confirmation of proper device placement and no significant leaks before discontinuing warfarin 1
• The need for ongoing aspirin therapy to prevent thromboembolic events and device-related thrombus formation 1
• The potential for alternative regimens, such as dual antiplatelet therapy from the beginning, for patients with contraindications to warfarin 1
• The ongoing risk of device-related thrombi and peri-device leaks, which necessitate regular follow-up screening 1. Overall, this regimen prioritizes the prevention of thromboembolic events and device-related complications while minimizing bleeding risks, and is supported by the most recent and highest quality evidence 1.

From the Research

Antiplatelet and Anticoagulant Therapy after Watchman Implantation

• The WATCHMAN device is a non-inferior alternative to warfarin for preventing embolic events in patients with atrial fibrillation 2.
• Post-procedural anticoagulation is necessary to avoid device-related thrombosis, typically involving warfarin and aspirin for 45 days after implantation 2, 3.
• If transesophageal echocardiography (TEE) at 45 days shows minimal residual peri-device flow and no device-related thrombus, warfarin can be stopped, and aspirin and clopidogrel can be given for six months, followed by aspirin indefinitely 2.
• For patients with an absolute contraindication to oral anticoagulation, antithrombotic therapy with aspirin and clopidogrel for six months, followed by daily aspirin indefinitely, may be a feasible alternative 2.
• Direct oral anticoagulants (DOACs) may also be used, although limited evidence suggests they are not inferior to warfarin following Watchman implantation 2.

Antithrombotic Regimens after Watchman Implantation

• The most commonly utilized regimen after Watchman implantation is warfarin followed by antiplatelet treatment 2.
• In cases with a high risk of bleeding, antiplatelets alone may be sufficient 2, 4.
• A study using aspirin alone as post-implant antithrombotic therapy after left atrial appendage occlusion with the AMPLATZER Cardiac Plug or Amulet device showed a low risk of device-related thrombosis and stroke 4.

Challenges and Future Directions

• Antithrombotic therapy after Watchman implantation can be complex, particularly in patients with contraindications to oral anticoagulation or those requiring concomitant medications 5.
• Further research is needed to tailor antithrombotic regimens to individual patient needs and to minimize the risk of bleeding and thrombotic complications 2, 3.