What is the indication for the Watchman (Left Atrial Appendage Closure) device in patients with non-valvular atrial fibrillation?

Indications for Watchman Device in Non-Valvular Atrial Fibrillation

The Watchman left atrial appendage closure device is indicated for patients with non-valvular atrial fibrillation who are at increased risk of stroke (CHA₂DS₂-VASc score ≥2 for men or ≥3 for women), and have contraindications to long-term oral anticoagulation or have an appropriate rationale to seek a non-pharmacological alternative to warfarin. 1

Patient Selection Criteria

The primary candidates for Watchman device implantation include:

• Patients with elevated stroke risk who are deemed unsuitable for prolonged anticoagulation 1
• Patients with contraindications to oral anticoagulation therapy, including:
  • History of major bleeding events
  • High risk of bleeding (HAS-BLED score ≥3)
  • Inability to maintain stable INR on warfarin
  • Medication non-compliance issues
  • Lifestyle considerations that make anticoagulation challenging 1

Evidence Supporting Watchman Use

The Watchman device has been evaluated in multiple clinical trials demonstrating:

• Non-inferiority to warfarin for the composite endpoint of stroke, systemic embolism, and cardiovascular death 1, 2
• Significantly lower hemorrhagic stroke rates compared to warfarin 1, 2
• Reduced cardiovascular death and reduced bleeding beyond the immediate post-procedural period 1

The EWOLUTION trial showed consistently low rates of stroke (1.3/100 patient-years, 83% reduction versus historic data) and major nonprocedural bleeding events (2.7/100 patient-years, 46% reduction) in high-risk patients, most of whom were contraindicated to oral anticoagulation 3.

Recent 2024 data comparing Watchman to DOACs in high-risk patients with prior major bleeding showed that Watchman was associated with significantly lower rates of major bleeding events, TIAs, and ischemic strokes over 5 years 4.

Guideline Recommendations

The 2019 AHA/ACC/HRS guidelines classify the recommendation for Watchman as Class IIb (may be considered) with Level B-NR evidence 1. This reflects that:

• Oral anticoagulation (preferably NOACs) remains the first-line therapy for stroke prevention in atrial fibrillation
• Watchman is considered for specific populations with contraindications or challenges with long-term anticoagulation

Procedural Considerations

The Watchman procedure involves:

• Percutaneous left atrial appendage occlusion under general anesthesia with TEE guidance
• Transseptal puncture, device sizing, and deployment at the ostium of the LAA 1

A multidisciplinary team approach is recommended for patient selection and management, including:

• Electrophysiologists
• Interventional cardiologists
• Neurologists
• Imaging experts
• Primary care providers
• Cardiac surgeons 1

Post-Procedure Management

The standard post-implantation anticoagulation regimen includes:

1. 0-45 days: Warfarin (target INR 2.0-3.0) + Aspirin (81-100mg daily)
2. 45 days-6 months: Dual antiplatelet therapy (DAPT): Aspirin (81-325mg daily) and Clopidogrel (75mg daily)
3. >6 months: Aspirin (81-325mg daily) indefinitely 1

A transesophageal echocardiography (TEE) is performed at 45 days to check for:

• Device position
• Peri-device leak (should be ≤5mm)
• Device-related thrombus 1

Potential Complications

Important complications to monitor include:

• Pericardial effusion (4.4-7.1% of patients)
• Device embolization
• Procedure-related ischemic stroke
• Device-related thrombus formation 1, 5

Clinical Pearls

• The left atrial appendage is the source of approximately 90% of thrombi in patients with non-valvular atrial fibrillation 1
• Operator experience significantly impacts complication rates 1
• Patients with absolute contraindications to OACs/DOACs may be managed with dual antiplatelet therapy (DAPT) alone 5
• The ASAP study demonstrated that LAA closure with the Watchman device can be safely performed without a warfarin transition in patients with contraindications to systemic oral anticoagulation 6

The Watchman device represents an important alternative for stroke prevention in carefully selected patients with non-valvular atrial fibrillation who cannot tolerate long-term anticoagulation or have compelling reasons to seek non-pharmacological options.