From the Guidelines
Oral Anticoagulant Therapy Duration after Watchman Implantation
Patients should typically stay on Oral Anticoagulant (OAC) therapy for at least 45 days after receiving a Watchman (Left Atrial Appendage Closure) device, as suggested by regulatory approvals based on RCT protocols 1.
- After 45 days, a transesophageal echocardiogram (TEE) is usually performed to assess for adequate closure of the left atrial appendage.
- If the TEE shows adequate closure, OAC therapy can be discontinued, and patients are often transitioned to antiplatelet therapy, such as aspirin and clopidogrel, for a duration of 6 months 1.
- The use of Direct Oral Anticoagulant (DOAC) administration at full or reduced dose has been proposed as a treatment alternative to warfarin, with some studies supporting its use without associated increases in device-related thrombosis or stroke 1.
- After 6 months, patients can usually be maintained on aspirin indefinitely, although the exact duration of OAC therapy may vary depending on individual patient factors, such as stroke risk and bleeding risk 1.
- It is essential to note that device-related thrombi can occur with an incidence of 1.7%–7.2% and are associated with a higher risk of ischemic stroke, making late 'rule-out' imaging approach necessary 1.
- Additionally, follow-up screening for peri-device leaks is relevant, as small leaks (0–5 mm) are present in ∼25% of patients and have been reported 1.
From the Research
Duration of Oral Anticoagulant Therapy after Watchman Device Implantation
- The duration of oral anticoagulant (OAC) therapy after Watchman device implantation is a topic of debate, with varying recommendations based on individual patient risk factors 2.
- According to a study published in the American Journal of Cardiovascular Disease, warfarin and aspirin are typically given for 45 days after implantation, followed by aspirin and clopidogrel for six months, and then aspirin indefinitely 2.
- The study suggests that 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 2.
- Another study published in the same journal notes that the use of direct oral anticoagulants (DOACs) may be more convenient than warfarin, with limited evidence suggesting they are not inferior following implantation of the device 2.
Factors Influencing Duration of OAC Therapy
- The duration of OAC therapy may depend on individual patient risk factors, including the risk of thromboembolism and bleeding 3, 4.
- A study published in Thrombosis and Haemostasis suggests that the duration of triple therapy (OAC, aspirin, and clopidogrel) should be dependent on the individual risk of thromboembolism and bleeding, as well as the clinical context in which the procedure is performed 4.
- Another study published in Internal and Emergency Medicine notes that the risk of bleeding may increase with the duration of triple therapy, and that accurate stratification of thromboembolic and bleeding risk may allow for optimization of antithrombotic treatment 3.
Persistence with OAC Therapy
- Studies have shown that patients with non-valvular atrial fibrillation who discontinue OAC therapy are at higher risk of complications such as stroke 5, 6.
- A study published in the American Journal of Cardiovascular Drugs found that approximately 47-72% of patients discontinued or switched OAC therapy within an average 9-month follow-up period 5.
- Another study published in BMJ Open found that nearly 25% of patients discontinued OAC therapy within 3 months, and 55% within 12 months, with a mean time to discontinuation of 255 days 6.