What is the recommended anticoagulation regimen for patients undergoing Transcatheter Aortic Valve Replacement (TAVR)?

Anticoagulation Regimen for Patients Undergoing TAVR

For patients undergoing Transcatheter Aortic Valve Replacement (TAVR), the recommended anticoagulation regimen is clopidogrel 75 mg daily for 3-6 months plus lifelong aspirin 75-100 mg daily, with modifications based on specific patient factors. 1

Standard Anticoagulation Protocol

Primary Regimen

• For patients without other indications for anticoagulation:
  • Clopidogrel 75 mg daily for 3-6 months (3 months for self-expanding valves, 6 months for balloon-expandable valves)
  • Aspirin 75-100 mg daily lifelong
  • This dual antiplatelet therapy (DAPT) approach is based on clinical trial protocols 1

Special Considerations

Patients with Atrial Fibrillation or Other Indications for Anticoagulation

• Continue oral anticoagulation (OAC) as per guidelines for AF in patients with prosthetic heart valves
• When using vitamin K antagonist (VKA):
  • Continuation of aspirin is reasonable
  • Consider avoiding additional antiplatelet therapy due to increased bleeding risk 1

Patients at Risk for Valve Thrombosis

• Vitamin K antagonist therapy may be considered for the first 3 months after TAVR
• Target INR of 2.5 (range 2.0-3.0) 1
• This is particularly important for patients at risk of AF or valve thrombosis

Evidence Analysis and Nuances

Recent evidence suggests that single antiplatelet therapy (SAPT) with aspirin alone may be associated with lower bleeding risk compared to DAPT without increasing thrombotic events. Multiple studies have shown:

• Higher risk for major/life-threatening bleeding with DAPT compared to SAPT 2, 3
• No significant difference in stroke or mortality rates between DAPT and SAPT 4

However, the current guidelines still recommend DAPT based on the original clinical trial protocols that established TAVR safety and efficacy 1.

Important Caveats and Pitfalls

1. Direct Oral Anticoagulants (DOACs): Oral direct thrombin inhibitors or anti-Xa agents should NOT be used in patients with mechanical valve prostheses (Class III: Harm) 1

2. Subclinical Leaflet Thrombosis: There is emerging concern about subclinical leaflet thrombus formation after TAVR. Patients on vitamin K antagonist therapy have shown lower rates of reduced leaflet motion compared to those on antiplatelet therapy alone 1

3. Bleeding Risk: The potential benefit of anticoagulation must be carefully weighed against bleeding risk, especially in elderly TAVR patients who often have multiple comorbidities

4. Practice Variation: Hospital prescribing patterns vary significantly (median frequency of DAPT 85.7%, with wide interquartile range) 5, highlighting the lack of definitive evidence for optimal regimens

Monitoring and Follow-up

• Echocardiography before discharge to establish baseline valve function
• Repeat echocardiography at 30 days and then annually
• Regular ECG monitoring for detection of asymptomatic AF and conduction defects 1

For patients with high bleeding risk or recent bleeding events, consider modifying the antiplatelet regimen by shortening the duration of DAPT or using SAPT alone, as recent evidence suggests similar efficacy with reduced bleeding complications.