What is the treatment approach for a patient with moderate to severe mitral regurgitation and atrial fibrillation?

Treatment Approach for Moderate to Severe Mitral Regurgitation with Atrial Fibrillation

For patients with moderate to severe mitral regurgitation and atrial fibrillation, the treatment strategy depends critically on whether the mitral regurgitation is primary (organic) or secondary (functional), with anticoagulation being mandatory in both scenarios and surgical intervention indicated when other cardiac surgery is planned or when specific criteria are met. 1

Immediate Anticoagulation Management

• Oral anticoagulation with warfarin (target INR 2.0-3.0) is the guideline-recommended therapy for patients with atrial fibrillation and clinically significant mitral regurgitation. 1
• Direct oral anticoagulants (DOACs) are NOT FDA-approved for moderate to severe mitral stenosis but may be considered for mitral regurgitation with atrial fibrillation, though evidence is limited. 2, 3
• In patients with moderate-to-severe mitral regurgitation (3-4+) and atrial fibrillation, DOACs show similar efficacy to warfarin for preventing thromboembolism but carry a 3.2-fold higher risk of major bleeding compared to mild-moderate disease. 3
• Given the increased bleeding risk with DOACs in severe mitral regurgitation, warfarin remains the safer choice and should be prioritized. 3

Distinguish Primary vs. Secondary Mitral Regurgitation

Primary (Organic) Mitral Regurgitation

• Surgery is indicated (Class I) in symptomatic patients with severe primary mitral regurgitation and LVEF >30%. 1
• Surgery is indicated (Class I) in asymptomatic patients with LV dysfunction (LVESD ≥45 mm and/or LVEF ≤60%). 1
• Mitral valve repair should be the preferred surgical technique when durable results are expected. 1
• Early mitral valve surgery should be considered in severe mitral regurgitation with preserved LV function and new-onset atrial fibrillation, even without symptoms, particularly when valve repair is feasible. 1

Secondary (Functional) Mitral Regurgitation

• Surgery is indicated (Class I) in patients with severe secondary mitral regurgitation undergoing CABG and LVEF >30%. 1
• Surgery may be considered (Class IIa) in patients with severe secondary mitral regurgitation and LVEF >30% who remain symptomatic despite optimal medical management (including CRT if indicated) and have low surgical risk. 1
• There is no conclusive evidence for survival benefit after isolated mitral valve intervention in secondary mitral regurgitation. 1
• The severity of secondary mitral regurgitation should be reassessed after optimized medical treatment including heart failure medications and cardiac resynchronization therapy. 1
• Percutaneous edge-to-edge repair may be considered in patients at high surgical risk, avoiding futility. 1

Critical Evidence on Percutaneous Intervention

• The COAPT trial (2018) showed that mitral repair reduced heart failure hospitalizations in patients with moderately severe/severe mitral regurgitation at 24 months. 1
• However, the MITRA-FR trial (2018) showed that mitral repair did not reduce mortality or heart failure hospitalizations in moderate severe/severe mitral regurgitation at 12 months. 1
• This divergence in trial results highlights that patient selection for percutaneous mitral repair is critical and should be guided by a Heart Team approach. 1

Atrial Fibrillation Management

Rate Control

• Beta-blockers are first-line for rate control in patients with mitral regurgitation and atrial fibrillation. 4, 5
• Alternative options include diltiazem, verapamil, or digoxin, particularly useful when beta-blockers are contraindicated. 4, 5

Rhythm Control Considerations

• Catheter ablation for atrial fibrillation in heart failure with reduced ejection fraction (HFrEF) reduced all-cause mortality or heart failure hospitalization in the CASTLE-HF trial (2018). 1
• Where appropriate, atrial fibrillation ablation should be considered to prevent recurrent atrial fibrillation, particularly in symptomatic patients. 1

Heart Failure Optimization (for Secondary MR)

• Optimize guideline-directed medical therapy for heart failure including ACE inhibitors/ARNs, beta-blockers, and mineralocorticoid receptor antagonists before considering isolated mitral intervention. 1
• Cardiac resynchronization therapy (CRT) should be implemented if indicated per heart failure guidelines. 1
• Reassess mitral regurgitation severity after medical optimization, as secondary mitral regurgitation is a dynamic condition. 1

Common Pitfalls to Avoid

• Do not use DOACs in patients with moderate to severe mitral stenosis—this is explicitly contraindicated and warfarin is mandatory. 2, 6, 7, 8
• Do not assume all moderate-to-severe mitral regurgitation requires immediate surgery; secondary mitral regurgitation requires medical optimization first. 1
• Do not overlook the need for Heart Team evaluation when considering percutaneous interventions, given conflicting trial data. 1
• Do not delay anticoagulation in patients with atrial fibrillation and mitral regurgitation—the thromboembolic risk is substantial. 1
• After mitral transcatheter edge-to-edge repair in patients with atrial fibrillation, DOACs may offer comparable efficacy and safety to warfarin, though more data are needed. 9