What is the treatment approach for a patient with symptomatic mitral regurgitation?

Treatment of Symptomatic Mitral Regurgitation

The treatment approach for symptomatic mitral regurgitation fundamentally depends on whether the regurgitation is primary (degenerative) or secondary (functional), with primary MR requiring surgical intervention and secondary MR requiring optimized medical therapy first, followed by consideration of intervention in carefully selected cases.

Critical First Step: Classification

• Echocardiography is mandatory to determine whether MR is primary or secondary, as this fundamentally changes the entire management strategy 1, 2
• Primary MR involves structural valve abnormalities (prolapse, flail leaflet, degenerative disease) 1
• Secondary MR results from left ventricular dysfunction causing leaflet malcoaptation despite structurally normal valves 1
• The severity must be quantified using an integrative approach including effective regurgitant orifice area (EROA ≥40 mm² for primary MR; ≥20 mm² for secondary MR) and regurgitant volume 1

Management of Symptomatic Primary (Degenerative) MR

Surgical Intervention is the Definitive Treatment

Surgery is indicated for all symptomatic patients with severe primary MR 1, 2

• Mitral valve repair is strongly preferred over replacement when technically feasible, as it improves outcomes and reduces mortality by approximately 70% 1, 3
• Surgery should be performed at experienced centers with high repair rates (≥80-90%) and low operative mortality (<1%) 3
• Early surgical referral before the onset of left ventricular dysfunction optimizes outcomes 2, 4, 5

Medical Therapy Has Limited Role

• There is no well-defined role for medical therapy as primary treatment in severe primary MR 5
• Diuretics are required for fluid overload manifestations like lower extremity edema 2
• ACE inhibitors should be included when heart failure symptoms are present 2
• Vasodilators can paradoxically worsen MR in mitral valve prolapse and should be avoided 6

Management of Symptomatic Secondary (Functional) MR

Optimized Medical Therapy is Mandatory First

Guideline-directed medical therapy (GDMT) must be optimized as the first step before considering any intervention 1, 2

• Start diuretics immediately for fluid overload 2
• Add ACE inhibitors or angiotensin receptor blockers 2
• Include aldosterone antagonists if heart failure symptoms persist 2
• Beta-blockers provide beneficial effects and may lessen MR severity 6
• The severity of secondary MR is dynamic and must be reassessed after medical optimization, as it changes with loading conditions, blood pressure, volume status, and heart rate 1, 2, 4

Cardiac Resynchronization Therapy (CRT)

• CRT should be considered in appropriate candidates, as it may reduce MR severity through increased closing force and resynchronization of papillary muscles 2, 4
• CRT was historically considered a mainstay of treatment for secondary MR in heart failure with reduced ejection fraction 1

Interventional Options After Medical Optimization

Surgery is indicated in patients with severe secondary MR undergoing coronary artery bypass grafting (CABG) and LVEF >30% 1, 2

• Surgery may be considered in patients with severe secondary MR and LVEF >30% who remain symptomatic despite optimal medical management (including CRT if indicated) and have low surgical risk 1
• Mitral valve repair is preferred, but replacement should be considered with unfavourable morphological characteristics (large interpapillary muscle distance, severe posterior leaflet tethering, LV end-diastolic diameter >65 mm) 1

Transcatheter Edge-to-Edge Repair (TEER)

Percutaneous edge-to-edge repair (MitraClip) may be considered in patients at high surgical risk who remain symptomatic despite optimal medical therapy 1, 2

• The COAPT trial resulted in a major paradigm shift for secondary MR management, demonstrating benefit in carefully selected patients 1
• This option should avoid futility—patients must have appropriate anatomy and reasonable life expectancy 1
• No conclusive evidence exists for survival benefit after mitral valve intervention in secondary MR, making patient selection critical 1

Common Pitfalls to Avoid

• Delaying surgical intervention in primary MR until severe symptoms or left ventricular dysfunction occurs leads to worse outcomes 2, 4
• Failing to recognize the dynamic nature of secondary MR can lead to inappropriate management decisions—always reassess severity after medical optimization 1, 2, 4
• Treating secondary MR with intervention before optimizing medical therapy and CRT violates the fundamental treatment algorithm 1
• Using vasodilators in primary MR with prolapse can worsen regurgitation 6

Follow-Up Protocol

• Patients with severe MR should have clinical evaluation every 6 months with annual echocardiography 2, 4
• Exercise echocardiography should be considered when exercise-induced symptoms are present, as secondary MR is dynamic 1, 2