What are the recommendations for anticoagulant therapy in patients with valvular and non-valvular heart disease?

Anticoagulation in Valvular and Non-Valvular Heart Disease

For mechanical heart valves, lifelong warfarin (vitamin K antagonist) is mandatory and non-negotiable—direct oral anticoagulants (DOACs) are contraindicated and dangerous in this population. 1, 2

Mechanical Heart Valves

Absolute Requirements

• All patients with mechanical valves require lifelong warfarin therapy—this is a Class I recommendation with no acceptable alternatives 1, 2, 3
• DOACs (dabigatran, rivaroxaban, apixaban) are explicitly contraindicated in mechanical valve patients due to increased thrombotic and bleeding complications demonstrated in the RE-ALIGN trial, which was terminated early for safety 1, 2

INR Targets by Valve Position

• Mechanical aortic valve (bileaflet or current-generation): Target INR 2.5 (range 2.0-3.0) 1, 3
• Mechanical mitral valve: Target INR 3.0 (range 2.5-3.5)—higher target due to increased thrombotic risk 1, 3
• Both aortic and mitral mechanical valves: Target INR 3.0 (range 2.5-3.5) 1
• Older-generation valves (caged ball/disk): Target INR 3.0 (range 2.5-3.5) plus aspirin 75-100 mg daily 3

Adjunctive Antiplatelet Therapy

• Adding low-dose aspirin (50-100 mg daily) to warfarin is reasonable in mechanical valve patients at low bleeding risk to further reduce thromboembolism 1
• Exercise caution in patients with history of gastrointestinal bleeding 1

Bridging Anticoagulation

• Use prophylactic-dose unfractionated heparin or LMWH (prophylactic or therapeutic dose) immediately post-operatively until therapeutic INR is achieved on warfarin 1

Bioprosthetic Valves

First 3 Months Post-Implantation

• Mitral bioprosthetic valve: Warfarin with target INR 2.5 (range 2.0-3.0) for first 3 months 1, 3
• Aortic bioprosthetic valve: Aspirin 50-100 mg daily is preferred over warfarin in patients with sinus rhythm and no other indication for anticoagulation 1
• Transcatheter aortic valve replacement (TAVR): Dual antiplatelet therapy with aspirin 75-100 mg plus clopidogrel 75 mg daily for first 6 months 1

After 3 Months

• Aspirin 75-100 mg daily is reasonable for all bioprosthetic valve patients in normal sinus rhythm long-term 1

Critical Exception

• If atrial fibrillation develops or other thrombotic risk factors emerge (prior thromboembolism, left ventricular dysfunction, hypercoagulable state, left atrial thrombus), switch to warfarin with target INR 2.5 (range 2.0-3.0) 1, 4

Mitral Valve Repair

Anticoagulation Strategy

• Aspirin 50-100 mg daily is preferred over warfarin for the first 3 months in patients with prosthetic annuloplasty band in normal sinus rhythm, due to lower thrombotic risk and reduced bleeding compared to prosthetic valves 4
• After 3 months, continue aspirin 75-100 mg daily long-term 4

Mandatory Switch to Warfarin

• Warfarin (INR 2.0-3.0) becomes mandatory if patient develops atrial fibrillation, has prior thromboembolism, left ventricular systolic dysfunction, hypercoagulable condition, or left atrial thrombus 4

Rheumatic Mitral Valve Disease

Anticoagulation Indications

• Warfarin with target INR 2.5 (range 2.0-3.0) is recommended for patients with rheumatic mitral valve disease complicated by atrial fibrillation or previous systemic embolism 1
• For patients with mitral stenosis and atrial fibrillation, warfarin is mandatory—this is considered "valvular AF" where DOACs are not appropriate 3

Pre-Procedural Management

• If left atrial thrombus is detected on TEE before percutaneous mitral balloon valvotomy: Administer warfarin with target INR 3.0 (range 2.5-3.5) until thrombus resolution documented by repeat TEE 1
• If thrombus does not resolve with warfarin, do not perform the procedure 1

Non-Valvular Atrial Fibrillation with Valvular Heart Disease

DOAC Use in Specific Valve Lesions

• DOACs (dabigatran, rivaroxaban, apixaban) may be used in non-valvular AF patients with aortic stenosis, aortic regurgitation, or mitral regurgitation—subanalyses show similar efficacy and safety to warfarin 5, 6, 7
• DOACs reduce stroke/systemic embolism (HR 0.76,95% CI 0.67-0.87) and intracranial hemorrhage (HR 0.42,95% CI 0.22-0.80) compared to warfarin in this population 7

Absolute Contraindications for DOACs

• Moderate to severe mitral stenosis: Continue warfarin—these patients were excluded from all landmark DOAC trials 5
• Mechanical valves: DOACs are contraindicated 1, 2, 5
• Rheumatic mitral stenosis: Warfarin is required 3

Bioprosthetic Valves and DOACs

• More evidence is needed before routinely recommending DOACs for patients with bioprosthetic valves, though ARISTOTLE trial subanalysis of apixaban showed no safety concerns 5
• Current guidelines favor warfarin for the initial 3-6 months post-bioprosthetic valve implantation 1, 3

Infective Endocarditis

Anticoagulation Approach

• Do not initiate routine anticoagulant or antiplatelet therapy for infective endocarditis unless a separate indication exists (e.g., mechanical valve, atrial fibrillation) 1
• If patient has mechanical valve and develops IE: Continue warfarin if deemed stable without neurologic complications; otherwise, consider temporary discontinuation 1

Non-Bacterial Thrombotic Endocarditis

• Full-dose IV unfractionated heparin or subcutaneous LMWH is suggested over no anticoagulation in patients with systemic or pulmonary emboli 1

Minor Procedures in Anticoagulated Patients

• Continue warfarin with therapeutic INR for minor procedures where bleeding is easily controlled (dental extractions, cataract removal) 1
• Bridging strategy should be individualized based on valve type, position, and patient thrombotic risk factors for major procedures 1

Critical Pitfalls to Avoid

• Never use DOACs in mechanical valve patients—this is associated with increased valve thrombosis and stroke 1, 2
• Do not extrapolate DOAC data from non-valvular AF to patients with moderate-severe mitral stenosis or rheumatic valve disease—these populations require warfarin 1, 5
• Do not underdose warfarin in elderly patients with mechanical valves out of bleeding fear—the thrombotic risk is prohibitive without adequate anticoagulation 2, 8
• Verify sinus rhythm before using aspirin-only strategy after valve repair—if AF develops, warfarin becomes mandatory 4