Indications for Watchman Left Atrial Appendage Closure Device
The Watchman device is indicated for patients with non-valvular atrial fibrillation who are at increased risk for stroke (CHA₂DS₂-VASc score ≥2 for men or ≥3 for women), are suitable for anticoagulation, and have a rationale for seeking a non-pharmacologic alternative to oral anticoagulation therapy. 1, 2
Patient Selection Criteria
The primary candidates for Watchman implantation include:
Patients with contraindications to long-term oral anticoagulation:
- 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 making anticoagulation challenging 2
Patients seeking a non-pharmacological alternative to warfarin who are otherwise eligible for oral anticoagulation but have a reasonable rationale to avoid long-term anticoagulation 1, 2
Evidence Supporting Efficacy
The Watchman device has demonstrated:
- Non-inferiority to warfarin for the composite endpoint of stroke, systemic embolism, and cardiovascular death 2, 3
- Significantly lower rates of hemorrhagic stroke compared to warfarin 3
- Reduced cardiovascular death and bleeding beyond the immediate post-procedural period 2, 3
The EWOLUTION trial showed consistently low rates of stroke (1.3/100 patient-years, representing an 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 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 2. 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
Post-Procedure Anticoagulation Protocol
Standard post-implantation anticoagulation regimen:
| Time Period | Recommended Regimen |
|---|---|
| 0-45 days | Warfarin (target INR 2.0-3.0) + Aspirin (81-100mg daily) |
| 45 days-6 months | Dual antiplatelet therapy: Aspirin (81-325mg daily) and Clopidogrel (75mg daily) |
| >6 months | Aspirin (81-325mg daily) indefinitely [2] |
Important Considerations and Potential Complications
- Procedural complications: Pericardial effusion (4.4-7.1%), device embolization, procedure-related ischemic stroke 2, 5
- Post-procedural concerns: Device-related thrombus formation (observed in 4.1% of patients) 2, 4
- Follow-up imaging: Transesophageal echocardiography at 45 days to check for device position, peri-device leak (should be ≤5mm), and device-related thrombus 2
Implementation Requirements
The FDA approval and professional society guidelines emphasize that Watchman implantation should be performed:
- By operators with appropriate training and experience
- Within a multidisciplinary team approach including electrophysiologists, interventional cardiologists, neurologists, imaging experts, and cardiac surgeons
- At institutions with established protocols for patient selection, procedural performance, and post-procedural care 1, 2
The defining principle is that LAA occlusion is an institutionally based therapy provided across multiple disciplines, with patient-centered care as the primary focus 1.