Antiplatelet Therapy in Severe Mitral Regurgitation
Patients with severe mitral regurgitation in normal sinus rhythm do NOT require antiplatelet therapy based on the severity of their regurgitation alone. 1
Primary Mitral Regurgitation Without Atrial Fibrillation
- No anticoagulation or antiplatelet therapy is indicated for patients with primary mitral regurgitation who maintain normal sinus rhythm, regardless of severity. 1
- Prospective trials have failed to demonstrate that antithrombotic therapy reduces stroke risk in mitral regurgitation patients without atrial fibrillation. 1
- This recommendation applies even to severe mitral regurgitation, as the valve pathology itself does not create a thrombotic risk in the absence of other indications. 1
Critical Distinction: Mitral Regurgitation vs. Mitral Stenosis
It is essential to distinguish mitral regurgitation from mitral stenosis, as they have fundamentally different anticoagulation requirements:
- Mitral stenosis requires anticoagulation even in sinus rhythm due to high thrombotic risk (20-fold increased stroke risk). 2
- Mitral regurgitation does NOT share this thrombotic risk profile and should not be anticoagulated based on severity alone. 1
- This is a common clinical pitfall—do not extrapolate mitral stenosis guidelines to mitral regurgitation patients. 1
When Antiplatelet or Anticoagulation IS Indicated
Atrial Fibrillation Development
- Once atrial fibrillation develops, anticoagulation becomes mandatory with warfarin targeting INR 2.0-3.0 (or DOACs, which are NOT contraindicated in mitral regurgitation). 1
- Maintenance of sinus rhythm after cardioversion is unlikely unless the mitral regurgitation is surgically corrected, making anticoagulation the preferred strategy. 3
Post-Mitral Valve Repair
- Anticoagulation with warfarin (INR 2.0-3.0) is required for the first 3 months following mitral valve repair, then discontinued if sinus rhythm is maintained. 3, 1
Post-Mechanical Valve Replacement
- Warfarin with target INR 2.5-3.5 PLUS aspirin 75-100 mg daily indefinitely. 1
Post-Bioprosthetic Valve Replacement
- Warfarin for first 3 months (INR 2.0-3.0), then aspirin 80 mg daily if no atrial fibrillation. 1
History of Systemic Embolism
- Anticoagulation (INR 2.0-3.0) is indicated in severe mitral regurgitation patients with documented systemic embolism. 1
Presence of Left Atrial Thrombus
- Anticoagulation is required if left atrial thrombus is identified on echocardiography. 3
Transcatheter Edge-to-Edge Repair (MitraClip) Considerations
For patients undergoing MitraClip procedures, the antithrombotic strategy differs from native valve disease:
- In sinus rhythm: Dual antiplatelet therapy (aspirin + clopidogrel) for 4 weeks, followed by aspirin monotherapy. 4
- With atrial fibrillation: Lifelong oral anticoagulation combined with a single antiplatelet agent for 4 weeks post-procedure. 4
- Recent observational data suggests oral anticoagulation monotherapy (without additional antiplatelet therapy) may have more favorable long-term outcomes in patients with an indication for anticoagulation. 5
Common Pitfalls to Avoid
- Do not anticoagulate isolated severe mitral regurgitation in sinus rhythm based on severity alone—this differs fundamentally from mitral stenosis management. 1
- Do not confuse rheumatic mitral valve disease (which may require anticoagulation even in sinus rhythm) with degenerative mitral regurgitation. 3
- Do not delay anticoagulation once atrial fibrillation develops, as this significantly increases thromboembolic risk. 3, 1
- Vasodilators including ACE-inhibitors are NOT recommended in chronic mitral regurgitation without heart failure, as there is no evidence of benefit. 3