The WATCHMAN device and post-implantation anticoagulation management. A review of key studies and the risk of device-related thrombosis.

Background: Ischemic stroke is a devastating complication of atrial fibrillation (Afib). Anticoagulation is the gold standard to prevent stroke and systemic embolization. However, many patients have a contraindication to oral anticoagulation. The WATCHMAN device, which closes the left atrial appendage, is non-inferior to warfarin to prevent embolic events in clinical trials. Post-procedural anticoagulation is needed to avoid device-related thrombosis. The use of anticoagulants after WATCHMAN implantation in patients with high bleeding risks has been a source of debate.

Objective: This article summarizes the current evidence on anticoagulation following the implantation of the WATCHMAN device, focusing on patients who have an absolute contraindication to oral anticoagulation.

Observation: The WATCHMAN device is efficacious and safe in preventing stroke and systemic embolization. Warfarin and aspirin are given for 45 days after implantation. If TEE at 45 days shows minimal residual peri-device flow (≤ 5mm) and no device-related thrombus, warfarin is stopped. This is followed by aspirin and clopidogrel for six months, then aspirin indefinitely. Antithrombotic therapy with aspirin and clopidogrel for six months followed by daily aspirin indefinitely may be feasible for patients with an absolute contraindication to OAC. DOACs are more convenient to use than warfarin, and limited evidence suggests that they are not inferior following implantation of the device.

Conclusion: Following the WATCHMAN implantation, the most often utilized regimen is warfarin followed by antiplatelet treatment. In cases where there is a high risk of bleeding, antiplatelets alone may be sufficient. More research is needed to tailor the existing antithrombotic regimen to the needs of patients.