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

Indications for Watchman (Left Atrial Appendage Closure) Procedure

The Watchman procedure is indicated for patients with non-valvular atrial fibrillation who are at increased risk for stroke (CHA₂DS₂-VASc score ≥3 for women or ≥2 for men) and have contraindications to long-term oral anticoagulation therapy or high bleeding risk (HAS-BLED score ≥3). 1

Patient Selection Criteria

The American Heart Association, American College of Cardiology, and Heart Rhythm Society recommend considering the Watchman procedure for:

• Patients with non-valvular atrial fibrillation who:
  • Have an elevated stroke risk (CHA₂DS₂-VASc score ≥2 for men or ≥3 for women)
  • AND are deemed unsuitable for prolonged anticoagulation 1
  • OR have an appropriate rationale to seek a non-pharmacological alternative to warfarin 1

Specific Indications

1. Contraindications to oral anticoagulation therapy:

   • 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

2. Alternative to long-term anticoagulation:

   • For patients seeking a non-pharmacological approach to stroke prevention
   • Patients with history of bleeding complications on anticoagulants

Clinical Evidence Supporting Indications

The Watchman device works by mechanically closing the left atrial appendage, which is the source of approximately 90% of thrombi in patients with non-valvular atrial fibrillation 1. Clinical evidence demonstrates:

• The device is non-inferior to warfarin for the composite endpoint of stroke, systemic embolism, and cardiovascular death 1
• Significantly lower hemorrhagic stroke rates compared to warfarin 1
• Reduced cardiovascular death and bleeding beyond the immediate post-procedural period 1

Recent evidence from 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 versus historic data) in high-risk patients, most of whom were contraindicated to oral anticoagulation 2.

Guideline Classification

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

Multidisciplinary Approach

Implementation of LAA occlusion programs requires a collaborative effort including:

• Electrophysiologists
• Interventional cardiologists
• Neurologists
• Imaging experts
• Primary care providers
• Cardiac surgeons 3

Post-Procedure Management

After Watchman implantation, patients typically follow this anticoagulation regimen:

• 0-45 days: Warfarin (target INR 2.0-3.0) + Aspirin (81-100mg daily)
• 45 days-6 months: Dual antiplatelet therapy (DAPT): Aspirin and Clopidogrel

• 6 months: Aspirin indefinitely 1

A transesophageal echocardiography (TEE) is performed at 45 days to check for device position, peri-device leak, and device-related thrombus 1.

Potential Complications

Important considerations include:

• Pericardial effusion (4.4-7.1% of patients)
• Device embolization
• Procedure-related ischemic stroke
• Device-related thrombus formation 1, 4

Emerging Evidence

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 5. This suggests that Watchman may be particularly beneficial for patients with a history of bleeding complications.