Is Deep Vein Thrombosis (DVT) prophylaxis necessary for a patient with a Watchman device implanted?

DVT Prophylaxis for Patients with Watchman Device Implantation

Patients with a Watchman device implantation do not require routine DVT prophylaxis beyond the standard post-procedural anticoagulation and antiplatelet regimen already prescribed for the device itself.

Post-Watchman Anticoagulation Protocol

The Watchman device, which occludes the left atrial appendage (LAA), already requires a specific anticoagulation/antiplatelet regimen to prevent device-related thrombosis (DRT). This regimen typically includes:

1. Initial 45 days post-implantation:

   • Warfarin (target INR 2-3) plus aspirin 1
   • At 45 days: Transesophageal echocardiogram (TEE) to check for device-related thrombus

2. If TEE shows no thrombus and minimal residual peri-device flow (≤5mm):

   • Discontinue warfarin
   • Continue with dual antiplatelet therapy (aspirin plus clopidogrel) for 6 months 1

3. After 6 months:

   • Aspirin monotherapy indefinitely 1

Alternative Regimens

For patients with contraindications to oral anticoagulation:

• Dual antiplatelet therapy (aspirin and clopidogrel) for 6 months followed by aspirin indefinitely may be considered 1, 2
• Direct oral anticoagulants (DOACs) may be used as an alternative to warfarin in the initial period, though evidence is more limited 1, 2

Risk Assessment for DVT Prophylaxis

When considering additional DVT prophylaxis beyond the standard Watchman anticoagulation protocol:

1. Assess individual VTE risk factors:

   • Age >60 years
   • Restricted mobility
   • History of VTE
   • Active cancer
   • Obesity
   • Other hypercoagulable states 3, 4

2. Consider bleeding risk:

   • Patients with Watchman devices often have elevated bleeding risk, which is frequently why the device was implanted in the first place 3
   • Adding additional anticoagulation would increase bleeding risk

Recommendations Based on Clinical Scenario

1. Hospitalized patient with Watchman device:

   • If already on the standard post-Watchman anticoagulation/antiplatelet regimen, additional DVT prophylaxis is generally unnecessary and may increase bleeding risk
   • If mechanical prophylaxis is desired, intermittent pneumatic compression (IPC) devices can be used 3, 4

2. Surgical patient with Watchman device:

   • For patients undergoing surgery who must temporarily discontinue their post-Watchman anticoagulation:
     • Use mechanical prophylaxis (IPC) during the perioperative period 3
     • Resume the appropriate phase of Watchman anticoagulation/antiplatelet therapy as soon as hemostasis is achieved

3. High-risk scenarios:

   • For patients with multiple additional risk factors for VTE (prolonged immobilization, active cancer, prior VTE):
     • Consider mechanical prophylaxis with IPC rather than additional pharmacological prophylaxis 4
     • Consult with both cardiology and hematology before adding any additional anticoagulants to the Watchman regimen

Important Considerations

• Device-related thrombosis: The risk of thrombus formation on the Watchman device can be as high as 7.2% per year and is associated with ischemic stroke 3
• Late thrombosis risk: Device-related thrombus can occur even years after implantation, highlighting the importance of maintaining the recommended antiplatelet therapy 5
• Bleeding risk: Most patients receiving Watchman devices have elevated bleeding risk, making additional anticoagulation potentially hazardous 3

Monitoring

• TEE is recommended at 45 days and 12 months post-implantation to assess for device-related thrombosis 2
• If device-related thrombosis is detected, treatment with LMWH or oral anticoagulants is recommended 2

The standard post-Watchman anticoagulation/antiplatelet regimen provides sufficient prophylaxis against both device-related thrombosis and venous thromboembolism for most patients, making additional DVT prophylaxis unnecessary and potentially increasing bleeding risk.