Watchman Left Atrial Appendage Closure: Indications and Protocol
The Watchman device is indicated for patients with non-valvular atrial fibrillation who have contraindications to long-term oral anticoagulation therapy, with a Class IIb recommendation and Level B-NR evidence. 1
Patient Selection Criteria
Primary Indications
- 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
Contraindications
- Valvular atrial fibrillation
- Left atrial appendage thrombus (would need resolution before procedure)
- Inability to tolerate short-term anticoagulation for at least 45 days post-procedure 1
Procedural Protocol
Pre-Procedure Assessment
- Transesophageal echocardiography (TEE) to:
- Rule out left atrial appendage thrombus
- Assess left atrial appendage anatomy for device sizing
- Measure left atrial appendage dimensions 2
Procedure
- Performed under general anesthesia with TEE guidance
- Transseptal puncture to access the left atrium
- Device deployment in the left atrial appendage
- Confirmation of proper positioning and seal 2
Post-Procedure Medication Regimen
The standard medication protocol following Watchman implantation is:
| Timeframe | Medication Regimen |
|---|---|
| 0-45 days | Warfarin (INR 2.0-3.0) + Aspirin (81-100mg daily) |
| 45 days-6 months | Dual antiplatelet therapy: Aspirin + Clopidogrel |
| >6 months | Aspirin indefinitely |
Follow-Up Protocol
- TEE at 45 days post-procedure to:
- Confirm device position
- Rule out device-related thrombus
- Assess for peridevice leaks
- If satisfactory seal is achieved at 45 days, warfarin is discontinued and replaced with dual antiplatelet therapy
- Additional TEE at 6 months to assess for late complications
- Some centers perform TEE at 12 months as well 1, 2
Efficacy and Safety
Efficacy
- The Watchman device has demonstrated non-inferiority to warfarin for stroke prevention in atrial fibrillation 3
- Recent evidence shows it may provide benefit in rates of bleeding events, TIAs, and ischemic strokes compared to DOACs in high-risk populations 4
- The EWOLUTION trial showed consistently low rates of stroke (1.3/100 patient-years, 83% reduction versus historic data) 5
Complications
- Pericardial effusion (4.4-7.1% of cases)
- Device embolization
- Procedure-related ischemic stroke
- Device-related thrombus formation (approximately 3.4% of patients) 1, 2
Special Considerations
Device-Related Thrombus Management
- If device-related thrombus is detected:
- Reinitiate oral anticoagulation or low molecular weight heparin
- Repeat TEE to confirm thrombus resolution 2
Alternative Post-Procedure Regimens
- DOACs have been shown to be a convenient and non-inferior substitute for warfarin in the post-procedure period 2
- Patients with absolute contraindications to oral anticoagulants may be managed with dual antiplatelet therapy alone, though this carries higher risk 2
Multidisciplinary Approach
- The FDA and professional societies recommend a multidisciplinary team approach for:
- Patient selection
- Procedural performance
- Post-procedural care
- Participation in a national registry for quality assessment 1
Clinical Pitfalls to Avoid
- Inappropriate patient selection (patients who can safely take long-term oral anticoagulation should generally continue medical therapy)
- Premature discontinuation of post-procedure anticoagulation/antiplatelet therapy increases risk of device-related thrombosis
- Inadequate imaging follow-up may miss complications requiring intervention
- Failure to recognize that the Watchman is an alternative, not first-line therapy for most patients with atrial fibrillation 1, 2