What is the typical anticoagulation strategy after Watchman (Left Atrial Appendage Closure Device) placement?

Anticoagulation After Watchman Device Placement

Standard Post-Procedural Anticoagulation Protocol

The American Heart Association recommends a three-phase anticoagulation regimen: warfarin (INR 2.0-3.0) plus aspirin 81-162 mg daily for at least 45 days, followed by dual antiplatelet therapy (aspirin plus clopidogrel) from 45 days to 6 months, then aspirin monotherapy indefinitely. 1

This protocol is based on the PROTECT-AF trial design, which demonstrated non-inferiority of the Watchman device to warfarin for preventing stroke, systemic embolism, and cardiovascular death (RR 0.62; 95% CI 0.35-1.25). 2 The hemorrhagic stroke risk was dramatically lower with the device compared to long-term warfarin (RR 0.09; 95% CI 0-0.45). 1

Phase 1: Days 0-45

• Warfarin (target INR 2.0-3.0) plus aspirin 81-162 mg daily 1, 3
• This initial period allows for endothelialization over the device surface to prevent device-related thrombosis 4
• Close INR monitoring is essential during this high-risk bleeding period, particularly in elderly patients 3
• Mandatory TEE at 45 days to evaluate for device-related thrombus and peridevice leak before discontinuing warfarin 1, 3

Phase 2: 45 Days to 6 Months

• Dual antiplatelet therapy (aspirin 81-162 mg plus clopidogrel 75 mg daily) 1
• Warfarin can only be discontinued if the 45-day TEE shows no device-related thrombus and minimal peridevice leak (≤5mm) 4
• Any peridevice leak detected, regardless of size, is associated with increased thromboembolism risk and requires continued anticoagulation 1, 3

Phase 3: After 6 Months

• Aspirin 81-162 mg daily indefinitely 1, 5
• A second TEE is recommended at 1 year for continued surveillance 1

Critical Monitoring Requirements

TEE Surveillance Schedule

• TEE must be performed at 45 days and 1 year after device placement to evaluate for device-related thrombus and peridevice leak 1
• Device-related thrombus occurs in 1.7-7.2% of patients and significantly increases stroke risk (HR 4.6 for high-grade thrombus) 3

High-Risk Patients Requiring Closer Surveillance

The following patient characteristics increase risk of device-related thrombus and warrant more intensive monitoring:

• Non-paroxysmal atrial fibrillation (OR 1.90-2.24) 1
• Renal insufficiency (OR 4.02) 1
• History of TIA or stroke (OR 2.31) 1
• Deep device implantation >10mm from pulmonary vein limbus (OR 2.41) 1

Alternative Anticoagulation Regimens

DOACs as Warfarin Alternatives

While warfarin remains the guideline-recommended anticoagulant, emerging evidence suggests DOACs may be feasible alternatives:

• Standard-dose rivaroxaban (20 mg daily) for 45 days showed low incidence of device-related thrombosis and bleeding events in a small retrospective study 6
• Low-dose dabigatran (110 mg twice daily) significantly decreased bleeding risk compared to warfarin (13.2% vs 34.8%, p=0.02) but increased device-related thrombus risk (15.8% vs 2.2%, p=0.03), suggesting this dose should be used with caution 7

Important caveat: No randomized trials have compared DOACs to warfarin post-Watchman implantation, and the 2024 ESC Guidelines note that with DOACs demonstrating similar bleeding rates to aspirin, the role of Watchman in current practice is unclear since device trials compared against warfarin, not modern DOACs. 1

Patients with Absolute Contraindications to Anticoagulation

For patients with absolute contraindications to even short-term anticoagulation:

• Dual antiplatelet therapy (aspirin plus clopidogrel) for 6 months followed by aspirin indefinitely may be feasible 4
• However, the FDA approval specifies that patients must be deemed suitable for at least short-term warfarin and can tolerate at least 45 days of post-procedural anticoagulation 1
• In a multicenter series of 20 patients with history of spontaneous major bleeding while on anticoagulation, short-term post-procedural anticoagulation was associated with low risk of recurrent spontaneous major bleeding when carefully managed by a multidisciplinary team 8
• In 63 patients with prior intracranial hemorrhage, 19% were managed with DAPT alone post-procedurally with 95% free of death, stroke, or major bleeding at 6 months, and no recurrent intracranial hemorrhage 9

Special Populations

Patients with Concurrent Coronary Artery Disease

Patients requiring dual antiplatelet therapy for stent thrombosis prevention should remain on DAPT beyond 6 months, not transition to aspirin monotherapy. 5, 3 This represents a deviation from the standard protocol and requires careful coordination between cardiology subspecialties.

Patients Over 85 Years

Patients over 85 have significantly higher procedural stroke risk and warrant closer monitoring during the anticoagulation period. 3

Common Pitfalls to Avoid

• Never discontinue warfarin at 45 days without TEE confirmation of no device-related thrombus and acceptable peridevice leak 3
• Any new neurological symptoms warrant immediate evaluation, as device-related thrombus-associated stroke risk is substantial 3
• Do not assume all peridevice leaks are benign - any leak, regardless of size, increases thromboembolism risk and may require continued anticoagulation 1, 3
• Monitor closely for bleeding during the initial 45-day warfarin period, particularly in elderly patients and those with prior bleeding history 3