What is the recommended anticoagulation (anti-coagulant) therapy for a patient with Rheumatic Heart Disease (RHD) and a history of atrial fibrillation or thromboembolic events?

Anticoagulation for Rheumatic Heart Disease

Patients with rheumatic heart disease (RHD) and atrial fibrillation require lifelong vitamin K antagonist (VKA) therapy with warfarin, targeting an INR of 2.5 (range 2.0-3.0), and direct oral anticoagulants (DOACs) are contraindicated in this population. 1, 2

Primary Recommendation: Vitamin K Antagonists

For RHD patients with atrial fibrillation, warfarin is the only acceptable anticoagulant with a Class I recommendation. 1, 2 This represents the highest level of guideline support from the ACC/AHA, and this recommendation applies regardless of whether the patient has rheumatic mitral stenosis specifically or other manifestations of RHD. 1

Target INR and Dosing

• Standard target INR: 2.5 (range 2.0-3.0) for most RHD patients with atrial fibrillation 1, 2, 3
• Initial warfarin dosing: 2-5 mg daily, with lower doses (2 mg) preferred in elderly patients 2, 3
• INR monitoring: Monthly once stable, with goal time in therapeutic range (TTR) >65-70% 2

Higher Intensity Anticoagulation for Specific Scenarios

If left atrial thrombus is present on transesophageal echocardiography, increase target INR to 3.0 (range 2.5-3.5) until thrombus resolution is documented. 2, 4 This higher intensity approach may also be considered for patients with recurrent systemic embolism despite adequate standard-intensity anticoagulation. 4, 5

Why DOACs Are Contraindicated in RHD

The INVICTUS trial definitively demonstrated that rivaroxaban is inferior to warfarin in RHD-associated atrial fibrillation. 6, 7 In this landmark study of 4,531 patients:

• Rivaroxaban resulted in 76 fewer days of survival compared to VKA therapy (restricted mean survival time: 1599 vs 1675 days; P<0.001) 7
• Higher mortality occurred with rivaroxaban (72 fewer days of survival; 95% CI -117 to -28) 7
• No bleeding advantage was observed with rivaroxaban compared to warfarin 7
• Permanent discontinuation was more common with rivaroxaban at all follow-up visits 7

This evidence directly contradicts the use of DOACs in RHD with atrial fibrillation, despite their proven efficacy in non-valvular atrial fibrillation. 6, 7 The pathophysiology of rheumatic valvular disease creates a fundamentally different thrombotic milieu that DOACs cannot adequately address. 6

Anticoagulation in RHD Patients WITHOUT Atrial Fibrillation

Even in sinus rhythm, certain RHD patients require anticoagulation:

Mandatory Indications (Class I)

• Left atrial thrombus on echocardiography - warfarin with INR 2.0-3.0 2, 5
• Previous systemic embolism - warfarin with INR 2.0-3.0 1, 2, 5

Strong Indications (Class IIa)

• Left atrial diameter ≥55 mm in rheumatic mitral stenosis - warfarin with INR 2.0-3.0 2, 5
• Spontaneous echo contrast in left atrium - warfarin with INR 2.0-3.0 2, 5

The left atrial diameter threshold of 55 mm is specifically established for rheumatic mitral valve disease and does not apply to other valvular conditions. 5 This recommendation carries Grade 2C evidence, reflecting clinical consensus despite limited randomized trial data. 5

Special Considerations for Procedures

If preprocedural transesophageal echocardiography shows left atrial thrombus before percutaneous mitral balloon valvotomy (PMBV):

• Postpone the procedure until thrombus resolution is documented 2
• Administer warfarin with target INR 3.0 (range 2.5-3.5) during this period 2, 4
• Perform repeat TEE to confirm thrombus resolution before proceeding 2, 4

Duration of Therapy

Anticoagulation is lifelong for RHD patients with any of the following: 2, 5

• Atrial fibrillation (paroxysmal, persistent, or permanent)
• Left atrial thrombus (current or previous)
• Previous systemic embolism
• Left atrial diameter ≥55 mm in rheumatic mitral stenosis

Critical Pitfalls to Avoid

Never prescribe DOACs for rheumatic mitral stenosis with atrial fibrillation - this is explicitly contraindicated based on the INVICTUS trial showing increased mortality. 6, 7 The randomized controlled trials that established DOAC efficacy specifically excluded patients with moderate-to-severe mitral stenosis. 1

Do not use CHADS2-VASc scoring to determine anticoagulation need in RHD - the presence of rheumatic heart disease itself, particularly mitral stenosis, is an automatic indication for anticoagulation regardless of CHADS2-VASc score. 1

Avoid aspirin monotherapy - aspirin alone is inadequate for stroke prevention in RHD with atrial fibrillation and should never be used as a substitute for warfarin. 1

Post-Bioprosthetic Valve Replacement Exception

After bioprosthetic mitral valve replacement for RHD, DOACs may be considered as an alternative to warfarin. 8 A recent observational study of 3,950 patients showed DOACs were associated with lower major bleeding (HR 0.76; 95% CI 0.62-0.94) and comparable effectiveness to warfarin at 5-year follow-up. 8 However, this applies only to patients who have undergone valve replacement, not to those with native rheumatic valvular disease. 8