Anticoagulation for Valvular Heart Disease
For patients with mechanical prosthetic valves, lifelong vitamin K antagonist (VKA) therapy with INR monitoring is mandatory, while those with bioprosthetic valves require VKA for 3-6 months post-operatively followed by aspirin, and native valvular disease patients need anticoagulation primarily when atrial fibrillation is present. 1
Mechanical Prosthetic Valves
All patients with mechanical prosthetic valves require lifelong VKA anticoagulation—this is non-negotiable. 1
INR Targets for Mechanical Valves:
Mechanical aortic valve (bileaflet or current-generation single-tilting disc) WITHOUT risk factors: Target INR 2.5 (range 2.0-3.0) 1
Mechanical aortic valve WITH risk factors (atrial fibrillation, previous thromboembolism, LV dysfunction, hypercoagulable state) OR older-generation valves (ball-in-cage): Target INR 3.0 (range 2.5-3.5) 1
Mechanical mitral valve replacement: Target INR 3.0 (range 2.5-3.5) regardless of risk factors 1
Dual mechanical valves (both aortic and mitral): Target INR 3.0 (range 2.5-3.5) 1
Additional Antiplatelet Therapy:
Add aspirin 75-100 mg daily to VKA therapy in all patients with mechanical valves when bleeding risk is low. 1 This combination reduces thromboembolic events compared to VKA alone. 1 However, exercise caution in patients with history of GI bleeding or other bleeding risk factors. 1
Critical Contraindications:
Direct oral anticoagulants (DOACs) are absolutely contraindicated in mechanical valve patients. 1 Specifically:
- Dabigatran is contraindicated (Class III recommendation) 1
- Anti-Xa DOACs (rivaroxaban, apixaban, edoxaban) have not been assessed and are not recommended 1
Bioprosthetic Valves (Surgical)
Early Post-Operative Period (First 3-6 Months):
VKA anticoagulation targeting INR 2.5 (range 2.0-3.0) is reasonable for 3-6 months after bioprosthetic mitral or aortic valve replacement in patients at low bleeding risk. 1 This recommendation reflects evidence showing lower stroke risk and mortality in patients receiving early anticoagulation after tissue valve implantation. 1
An alternative approach for aortic bioprosthetic valves in patients with sinus rhythm and no other indication for anticoagulation is aspirin 50-100 mg daily for the first 3 months. 1
For mitral bioprosthetic valves, VKA therapy (INR 2.5, range 2.0-3.0) is preferred over aspirin alone for the first 3 months. 1
Long-Term Management (After 3-6 Months):
Aspirin 75-100 mg daily is reasonable for all patients with bioprosthetic valves in normal sinus rhythm without other indications for anticoagulation. 1 This continues indefinitely. 1
Continue VKA indefinitely if atrial fibrillation develops or persists after bioprosthetic valve replacement. 1
Transcatheter Aortic Valve Implantation (TAVI)
For patients with bioprosthetic TAVI at low bleeding risk, two reasonable options exist for the first 3-6 months: 1
- Dual antiplatelet therapy with aspirin 75-100 mg plus clopidogrel 75 mg daily 1
- VKA anticoagulation targeting INR 2.5 1
Low-dose rivaroxaban (10 mg daily) plus aspirin is contraindicated in TAVI patients without other indications for anticoagulation. 1 This is based on trial data showing increased bleeding without benefit.
Native Valvular Heart Disease
Rheumatic Mitral Valve Disease:
Long-term VKA therapy (target INR 2.5, range 2.0-3.0) is recommended for patients with rheumatic mitral valve disease and atrial fibrillation or history of systemic embolism. 2 This applies regardless of hemodynamic severity of the valve lesion. 3
If systemic embolism occurs despite therapeutic INR, add aspirin 75-100 mg daily to the VKA regimen. 2
Mitral Valve Prolapse:
No antithrombotic therapy is recommended for mitral valve prolapse without history of systemic embolism, unexplained TIAs, or atrial fibrillation. 2
For MVP with documented unexplained TIAs, use long-term aspirin 50-162 mg daily. 2
Other Native Valve Disease:
For patients with native aortic stenosis, aortic regurgitation, or mitral regurgitation who develop atrial fibrillation, anticoagulation decisions follow standard AF guidelines. DOACs may be used in these patients as they do not have "valvular AF" by guideline definitions. 4 However, patients with moderate-to-severe mitral stenosis should receive warfarin, not DOACs, as they were excluded from DOAC trials. 4
Valve Repair
For mitral valve repair with prosthetic band in normal sinus rhythm, use antiplatelet therapy for the first 3 months rather than VKA. 1
For aortic valve repair, use aspirin 50-100 mg daily rather than VKA. 1
Critical Management Principles
INR Monitoring:
Specify a single INR target value for each patient rather than just a range. 1 The acceptable range includes 0.5 INR units on each side of the target. This approach reduces the likelihood of INR values consistently near boundaries and minimizes fluctuations, which are associated with increased complications. 1
Dedicated anticoagulation clinics result in lower complication rates than standard care and are cost-effective. 1 Self-monitoring with home INR devices is appropriate for educated and motivated patients. 1
Minor Procedures:
For patients with mechanical valves undergoing minor procedures (dental extractions, cataract removal) where bleeding is easily controlled, continue VKA anticoagulation with therapeutic INR. 1 Do not routinely bridge or interrupt therapy.
Thromboembolic Events Despite Adequate Anticoagulation:
For mechanical AVR patients experiencing stroke/embolism while in therapeutic range, either increase INR target from 2.5 to 3.0 (range 2.5-3.5) OR add aspirin 75-100 mg daily after assessing bleeding risk. 1
For mechanical MVR patients experiencing stroke/embolism while in therapeutic range, either increase INR target from 3.0 to 4.0 (range 3.5-4.0) OR add aspirin 75-100 mg daily after assessing bleeding risk. 1
Common Pitfalls to Avoid
Never use DOACs in patients with mechanical valves—this has been associated with increased thrombotic and bleeding complications. 1 The RE-ALIGN trial with dabigatran was terminated early due to harm.
Do not assume all "valvular heart disease" requires warfarin over DOACs. 4 Only rheumatic mitral stenosis, mechanical valves, and recent valve surgery/repair constitute true contraindications to DOACs in the AF population. Patients with aortic stenosis, aortic regurgitation, or mitral regurgitation can receive DOACs for AF. 4
Avoid inadequate anticoagulation intensity in mechanical mitral valves—these always require INR 3.0, not 2.5. 1 The mitral position carries higher thrombotic risk than aortic.