Watchman Procedure for Non-Valvular Atrial Fibrillation
The Watchman procedure is indicated for patients with non-valvular atrial fibrillation who are at increased risk of stroke (CHA₂DS₂-VASc score ≥3 for women or ≥2 for men) and have contraindications to long-term oral anticoagulation therapy or high bleeding risk. 1
Indications
Primary candidates:
FDA-approved indication:
- Patients with non-valvular AF who:
- Are at increased risk for stroke based on CHADS₂ or CHA₂DS₂-VASc scores
- Are deemed suitable for warfarin
- Have an appropriate rationale to seek a non-pharmacological alternative to warfarin 2
- Patients with non-valvular AF who:
Procedure Details
The Watchman is a percutaneous left atrial appendage occlusion (LAAO) device that works by mechanically closing the left atrial appendage, which is the source of approximately 90% of thrombi in patients with non-valvular AF 2.
Pre-Procedure Assessment
- Calculate CHA₂DS₂-VASc score to assess stroke risk
- Calculate HAS-BLED score to evaluate bleeding risk
- Evaluate anticoagulation status and history
- Transesophageal echocardiography (TEE) to assess LAA anatomy and rule out existing thrombus
Procedure Steps
- The procedure is performed under general anesthesia with TEE guidance
- Transseptal puncture to access the left atrium
- Device sizing based on LAA measurements
- Deployment of the Watchman device at the ostium of the LAA
- Confirmation of proper positioning and stability
Post-Procedure Management
Standard Anticoagulation Regimen
| Time | 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 (81-325mg daily) and Clopidogrel (75mg daily) |
| >6 months | Aspirin (81-325mg daily) indefinitely |
At 45 days, TEE is performed to check for:
- Device position
- Peri-device leak (should be ≤5mm)
- Device-related thrombus 1
For patients with absolute contraindications to oral anticoagulants, dual antiplatelet therapy may be considered immediately after implantation 3, 4
Efficacy and Safety
Efficacy
- The PROTECT AF and PREVAIL trials demonstrated non-inferiority to warfarin for the composite endpoint of stroke, systemic embolism, and cardiovascular death 1
- Meta-analysis showed comparable rates of composite primary efficacy outcomes, significantly lower hemorrhagic stroke rates, and reduced cardiovascular death 1
- In the EWOLUTION registry (real-world data), stroke rates were reduced by 83% compared to expected rates based on CHA₂DS₂-VASc scores 5
Complications and Risks
- Pericardial effusion: 4.4-7.1% of patients 2, 1
- Device embolization 2, 1
- Procedure-related ischemic stroke 2, 1
- Device-related thrombus formation: up to 7.2% per year 2, 1
- Incomplete endothelialization of the device, which may occur even after the expected 45-day period 6
Important Considerations
- A multidisciplinary team approach is recommended for patient selection and management 2
- Operator experience significantly impacts complication rates (learning curve effect) - serious pericardial effusions occur in 7.1% of the first 3 implant patients at each site compared with 4.4% of subsequent patients 2
- No randomized trials have compared Watchman with NOACs - current evidence is primarily against warfarin 2
- Thrombus formation on LAAO devices is not uncommon and is associated with a risk of ischemic stroke during follow-up 2
Guideline Recommendations
- The 2019 AHA/ACC/HRS guidelines classify the recommendation for Watchman as Class IIb (may be considered) 1
- The American Heart Association/American Stroke Association 2014 Guidelines state that LAA closure may be considered for high-risk patients with AF who are deemed unsuitable for prolonged anticoagulation 2
The Watchman procedure represents an important alternative for stroke prevention in carefully selected patients with non-valvular atrial fibrillation who cannot tolerate long-term oral anticoagulation.