What anticoagulation is used for patients with Atrial Fibrillation (AFib) and a history of a prosthetic heart valve?

Anticoagulation for Patients with Atrial Fibrillation and Prosthetic Heart Valves

For patients with atrial fibrillation and a mechanical heart valve, warfarin is the only recommended anticoagulant with a target INR based on the type and location of the prosthesis. 1

Mechanical Heart Valves

Recommended Anticoagulation

• Warfarin is mandatory for all patients with mechanical prosthetic heart valves 1
• Direct thrombin inhibitor dabigatran should NOT be used with mechanical heart valves (Class III: Harm) 1
• Target INR depends on valve type and position:
  • Aortic position with St. Jude Medical bileaflet valve: Target INR 2.5 (range 2.0-3.0) 2
  • Mitral position with tilting disk or bileaflet valves: Target INR 3.0 (range 2.5-3.5) 2
  • Caged ball or caged disk valves: Target INR 3.0 (range 2.5-3.5) plus aspirin 75-100 mg/day 2

Monitoring and Management

• INR should be determined at least weekly during initiation of therapy and monthly when anticoagulation is stable 1
• Bridging therapy with unfractionated heparin or low-molecular-weight heparin is recommended for patients undergoing procedures requiring interruption of warfarin 1

Bioprosthetic Heart Valves

Recommended Anticoagulation

• For patients with AF and bioprosthetic valves:
  • Warfarin (INR 2.0-3.0) is recommended for the first 3 months after valve insertion 2
  • After 3 months, anticoagulation options include:
    • Warfarin (INR 2.0-3.0) 1
    • Direct oral anticoagulants (DOACs) may be considered 1, 3

Evidence for DOACs in Bioprosthetic Valves

• Limited data from ARISTOTLE trial suggests apixaban may be a reasonable alternative to warfarin in patients with AF and prior bioprosthetic valve replacement 3
• The European Heart Rhythm Association states that NOACs may be used in patients with bioprosthetic valves after the initial 3-month period 1
• Recent retrospective data suggests DOACs may be safe and effective alternatives to warfarin in the early postoperative period after bioprosthetic valve replacement 4

Valve Repair

• For patients with AF after valve repair:
  • Warfarin (INR 2.0-3.0) for the first 3 months after mitral valve repair 2
  • After 3 months, DOACs may be considered based on limited evidence 1, 3

Common Pitfalls and Caveats

1. Terminology confusion: "Non-valvular AF" does not exclude all valve disease - it specifically excludes moderate-severe mitral stenosis and mechanical valves 5

2. DOAC contraindications: Never use DOACs in patients with:

   • Mechanical heart valves 1
   • Moderate to severe mitral stenosis 1

3. Bridging therapy: For patients with mechanical heart valves undergoing procedures:

   • Always use bridging therapy with heparin or LMWH when interrupting warfarin 1
   • For bioprosthetic valves, bridging decisions should balance stroke and bleeding risks 1

4. Monitoring intensity: More frequent INR monitoring is required during:

   • Initiation of therapy
   • Medication changes (especially antibiotics)
   • Dietary changes
   • Illness 1

5. Dual therapy considerations: When antiplatelet therapy is needed alongside anticoagulation:

   • Increases bleeding risk significantly
   • Consider lower INR targets and shorter duration of dual therapy when possible 1

By following these evidence-based recommendations, clinicians can optimize anticoagulation management for patients with AF and prosthetic heart valves to reduce the risk of thromboembolism while minimizing bleeding complications.