What is the Watchman device used for in patients with atrial fibrillation (AFib)?

The Watchman Device for Atrial Fibrillation

The Watchman device is a left atrial appendage closure (LAAC) device designed to prevent stroke in patients with non-valvular atrial fibrillation who have contraindications to long-term oral anticoagulation therapy. 1 It serves as a mechanical alternative to anticoagulants by permanently sealing off the left atrial appendage (LAA), which is the most common site of thrombus formation in atrial fibrillation patients.

Mechanism and Purpose

• The device works by physically occluding the LAA, preventing blood clots from forming and escaping into the circulation where they could cause strokes or systemic embolism 2
• In atrial fibrillation, the LAA is responsible for approximately 90% of thrombi that form in the left atrium
• By closing off this appendage, the Watchman device aims to reduce stroke risk without the need for lifelong anticoagulation

Indications and Patient Selection

The Watchman device is indicated for:

• Patients with non-valvular atrial fibrillation at increased risk of stroke (CHA₂DS₂-VASc score ≥2 for men or ≥3 for women) 1
• Patients who have contraindications to long-term oral anticoagulation therapy, such as:
  • History of major bleeding events
  • High bleeding risk (HAS-BLED score ≥3)
  • Inability to maintain stable INR on warfarin
  • Poor medication adherence or tolerance 1

Efficacy and Evidence

The Watchman device has demonstrated:

• Significantly lower rates of hemorrhagic stroke compared to warfarin 1
• Reduced cardiovascular death and major bleeding beyond the immediate post-procedural period 1
• In the EWOLUTION trial, patients with the Watchman device showed:
  • 83% reduction in stroke rates (1.3/100 patient-years) versus historic data
  • 46% reduction in major nonprocedural bleeding events (2.7/100 patient-years) 3

Post-Procedure Management

After Watchman implantation, patients typically follow this medication regimen:

1. First 45 days: Warfarin (INR 2.0-3.0) plus aspirin (81-100mg daily)
2. 45 days to 6 months: Dual antiplatelet therapy (aspirin plus clopidogrel)
3. Beyond 6 months: Aspirin indefinitely 1

Transesophageal echocardiography (TEE) is recommended at:

• 45 days post-procedure
• 6 months
• Sometimes at 12 months 1, 2

Potential Complications

Important risks to be aware of include:

• Device-related thrombosis (occurs in approximately 3.4% of patients) 1
• Pericardial effusion (4.4-7.1% of cases)
• Device embolization
• Procedure-related ischemic stroke 1, 2

Current Guideline Recommendations

The American Heart Association/American College of Cardiology/Heart Rhythm Society gives the Watchman device a Class IIb recommendation (may be considered) with Level B-NR evidence for patients with non-valvular atrial fibrillation who have contraindications to long-term oral anticoagulation 1.

Special Considerations

• For patients with absolute contraindications to oral anticoagulants, a modified post-procedure regimen of dual antiplatelet therapy for six months followed by aspirin indefinitely may be considered 4
• A multidisciplinary team approach is recommended for patient selection, procedural performance, and post-procedural care 1
• Direct oral anticoagulants (DOACs) are being studied as alternatives to warfarin in the post-implantation period, with limited evidence suggesting they may be non-inferior 4

Emerging Evidence

The ongoing CHAMPION-AF trial is comparing the Watchman FLX device directly to DOACs in patients with atrial fibrillation who are eligible for oral anticoagulation, which may potentially expand the indications for the device beyond those with contraindications to anticoagulation 5.