What is the recommended antithrombotic regimen for patients post-Watchman procedure, including Non-Vitamin K Antagonist Oral Anticoagulants (NOACs) and Dual Antiplatelet Therapy (DAPT)?

Post-Watchman Antithrombotic Regimen Management

The recommended antithrombotic regimen after Watchman implantation is a short period of triple antithrombotic therapy (up to 1 week) followed by dual antithrombotic therapy with a NOAC and a single antiplatelet agent (preferably clopidogrel) for up to 45 days, then dual antiplatelet therapy for 6 months, and finally lifelong aspirin therapy. 1, 2

Standard Post-Watchman Antithrombotic Protocol

• After Watchman implantation, periprocedural dual antiplatelet therapy (DAPT) consisting of aspirin and clopidogrel for up to 1 week is recommended 1
• Following this initial period, patients should receive:
  • 45 days of anticoagulation (warfarin or NOAC) plus aspirin 2
  • 6 months of DAPT (aspirin plus clopidogrel) after anticoagulation is discontinued 2
  • Lifelong aspirin therapy after DAPT is completed 2

NOAC-Based Regimens

• For patients receiving a NOAC after Watchman implantation:
  • After a short period of triple therapy (up to 1 week), dual antithrombotic therapy (DAT) is recommended as the default strategy using a NOAC at the recommended dose for stroke prevention plus a single antiplatelet agent (preferably clopidogrel) 1
  • When rivaroxaban is used and bleeding risk is high, rivaroxaban 15 mg once daily should be considered instead of 20 mg once daily for the duration of concomitant antiplatelet therapy 1
  • For dabigatran in high bleeding risk patients (HAS-BLED ≥3), 110 mg twice daily should be considered instead of 150 mg twice daily 1
  • Standard-dose rivaroxaban (20 mg daily) has been shown to be feasible with low incidence of thrombotic and bleeding complications in small studies 3

Risk-Stratified Approach

• For patients at high ischemic/thrombotic risk and low bleeding risk:

  • Triple therapy (OAC + DAPT) may be extended up to 1 month 1
  • Followed by dual therapy (OAC + single antiplatelet) up to 12 months 1

• For patients at low ischemic/thrombotic risk or high bleeding risk:

  • Shorter duration of triple therapy or immediate dual therapy (OAC + single antiplatelet) is preferred 1
  • Dual therapy should be continued for up to 6 months 1

Special Considerations

• Discontinuation of all antiplatelet therapy is recommended after 12 months, with continuation of OAC alone at full stroke-prevention doses 1
• For patients with absolute contraindication to OAC, DAPT with aspirin and clopidogrel for 6 months followed by aspirin indefinitely may be feasible 2
• Ticagrelor or prasugrel as part of triple antithrombotic therapy is not recommended 1
• For patients with history of intracranial hemorrhage, WATCHMAN implantation followed by 6 months of antithrombotic therapy has been shown to be safe in retrospective studies 4
• Some evidence suggests that shortened periods of anticoagulants and antiplatelets may be considered in patients with high bleeding risk 5

Follow-up Assessment

• Transesophageal echocardiography (TEE) should be performed at 45 days post-implantation 2
• If TEE shows minimal residual peri-device flow (≤5mm) and no device-related thrombus, anticoagulation can be discontinued and DAPT initiated 2
• Additional TEE follow-up at 6 months and 12 months may be considered to detect device-related thrombosis or peri-device leak 3

Bleeding Risk Reduction Strategies

• Use radial artery approach as default vascular access 1
• Administer proton pump inhibitors in patients on DAPT at higher-than-average risk of gastrointestinal bleeds 1
• Adjust anticoagulant doses according to body weight and renal function, especially in women and older patients 1