What is the recommended anticoagulation regimen after Watchman (Left Atrial Appendage Closure Device) implantation?

Anticoagulation Regimen After Watchman Implantation

The recommended anticoagulation regimen after Watchman implantation is warfarin (INR 2.0-3.0) plus aspirin (81-100mg daily) for 45 days, followed by dual antiplatelet therapy (aspirin plus clopidogrel) for 6 months, and then aspirin indefinitely. 1

Standard Anticoagulation Protocol

The standard post-Watchman anticoagulation protocol follows a three-phase approach:

1. Initial phase (0-45 days):

   • Warfarin (target INR 2.0-3.0) plus low-dose aspirin (81-100mg daily)
   • Transesophageal echocardiography (TEE) at 45 days to assess for:
     • Device position and stability
     • Presence of device-related thrombus
     • Peri-device leak (should be ≤5mm)

2. Intermediate phase (45 days-6 months):

   • If TEE shows proper device position with minimal or no leak (≤5mm) and no thrombus
   • Discontinue warfarin and switch to dual antiplatelet therapy (DAPT):
     • Aspirin (81-100mg daily) plus clopidogrel (75mg daily)

3. Long-term phase (>6 months):

   • Discontinue clopidogrel
   • Continue aspirin (81-100mg daily) indefinitely 1

Alternative Anticoagulation Strategies

While the standard protocol is backed by the strongest evidence, several alternative approaches have been used in real-world practice:

DOAC-Based Regimens

• NOACs/DOACs have been proposed as alternatives to warfarin in the initial 45-day period
• Limited evidence suggests standard-dose rivaroxaban may be feasible 2
• However, caution is warranted with low-dose dabigatran (110mg twice daily), which showed increased risk of device-related thrombus compared to warfarin (15.8% vs 2.2%) 3

Shortened Antiplatelet Therapy

• For patients with high bleeding risk, shortened periods of DAPT (6 weeks instead of 6 months) may be considered 4
• Some observational data supports reduced duration of both anticoagulant and antiplatelet therapy 5

Monitoring and Follow-up

Regular monitoring is essential to ensure proper device function and absence of complications:

• TEE at scheduled intervals:

  • 45 days (mandatory to assess for device-related thrombus before discontinuing anticoagulation)
  • 6 months (recommended)
  • 12 months (sometimes performed) 1

• If device-related thrombus is detected:

  • Continue or restart anticoagulation
  • Repeat TEE after 3-4 weeks to confirm thrombus resolution 1

Important Considerations and Caveats

• Device-related thrombus: Occurs in approximately 2-5% of patients and increases stroke risk. Risk factors include:

  • Non-paroxysmal atrial fibrillation
  • Renal insufficiency
  • History of TIA or stroke
  • Deep device implantation
  • Left ventricular dysfunction
  • Incomplete LAA sealing 1

• Peridevice leak: Common (26-57% of patients) and associated with increased thromboembolic risk 1

• Bleeding risk: Major bleeding is a significant concern, especially since many Watchman recipients have contraindications to long-term oral anticoagulation 6

• Patient selection: The Watchman device is primarily indicated for patients with non-valvular atrial fibrillation who have contraindications to long-term oral anticoagulation therapy 1

The anticoagulation regimen after Watchman implantation requires careful balancing of thromboembolic and bleeding risks during the critical endothelialization period of the device, with the standard protocol providing the most robust evidence for safety and efficacy.