From the Guidelines
After Watchman device implantation, patients should receive warfarin plus aspirin 81-325 mg daily for 45 days post-procedure, followed by dual antiplatelet therapy with clopidogrel 75 mg daily plus aspirin for another 4.5 months, and then aspirin 81-325 mg indefinitely, as supported by the 2024 ESC guidelines for the management of atrial fibrillation 1. The anticoagulation regimen post-Watchman implantation is crucial to prevent device-related thrombus formation and ensure proper endothelialization of the device.
- The initial 45-day regimen of warfarin plus aspirin is designed to maintain an INR of 2.0-3.0, as suggested by regulatory approvals based on RCT protocols 1.
- A 45-day follow-up transesophageal echocardiogram (TEE) is necessary to confirm proper device placement and rule out significant peridevice leaks before discontinuing warfarin and switching to dual antiplatelet therapy 1.
- The use of dual antiplatelet therapy with clopidogrel 75 mg daily plus aspirin for 4.5 months after the initial 45-day period is supported by observational studies, which have shown similar thromboembolic event rates and bleeding complications compared to ongoing anticoagulation 1.
- The long-term use of aspirin 81-325 mg daily is recommended to maintain antiplatelet therapy and prevent device-related thrombus formation, as the risk of thrombus formation decreases over time as the device becomes incorporated into the heart tissue 1.
- For patients with contraindications to warfarin, an alternative regimen of dual antiplatelet therapy with aspirin plus clopidogrel may be used from the beginning, as supported by observational studies 1.
From the Research
Anticoagulation Regimens Post-WATCHMAN Implantation
- The WATCHMAN device is a non-inferior alternative to warfarin for preventing embolic events in patients with atrial fibrillation 2.
- Post-procedural anticoagulation is necessary to avoid device-related thrombosis, with warfarin and aspirin typically given for 45 days after implantation 2, 3.
- If transesophageal echocardiography (TEE) at 45 days shows minimal residual peri-device flow and no device-related thrombus, warfarin can be stopped, followed by aspirin and clopidogrel for six months, and then aspirin indefinitely 2, 4.
Comparison of Anticoagulation Regimens
- Direct oral anticoagulants (DOACs) may be a viable alternative to warfarin, with limited evidence suggesting they are not inferior following WATCHMAN implantation 2, 5.
- Dual antiplatelet therapy (DAPT) for 3-6 months is commonly used in real-world practice, with some studies suggesting short-term DAPT or single antiplatelet therapy may be sufficient 3, 6.
- The choice of anticoagulant regimen does not appear to affect safety or efficacy outcomes, with bleeding and thromboembolic events being infrequent and unrelated to anticoagulant choice or prior major bleeding 5, 6.
Special Considerations
- Patients with a high risk of bleeding may be treated with antiplatelets alone, although more research is needed to tailor antithrombotic regimens to individual patient needs 2, 3.
- The WATCHMAN device can be safely implanted in patients with a relative or absolute contraindication to oral anticoagulation, with low rates of device thrombus, stroke, and major bleeding reported in clinical trials 4, 6.