What is the management of mitral regurgitation?

Management of Mitral Regurgitation

The management of mitral regurgitation fundamentally depends on distinguishing primary (degenerative) from secondary (functional) MR through echocardiography, as this classification completely determines the treatment pathway—with surgery being the definitive treatment for severe primary MR and guideline-directed medical therapy being mandatory first-line for secondary MR. 1, 2

Initial Diagnostic Assessment

Echocardiography is essential to classify MR as primary versus secondary, as this distinction completely changes the management algorithm. 1, 3

• Severe primary MR is defined by: vena contracta ≥7 mm, EROA ≥0.4 cm², regurgitant fraction ≥50%, and regurgitant volume ≥60 mL/beat 1, 2
• Severe secondary MR has a lower threshold: EROA ≥0.3 cm² when the regurgitant orifice is elliptical 1, 3
• Use cardiovascular magnetic resonance (CMR) when echocardiographic measurements are ambiguous or uncertain to quantify ventricular function and MR severity 1, 2
• Perform exercise echocardiography in patients with exercise-induced symptoms to assess dynamic worsening of MR 1, 3

Management of Primary (Degenerative) MR

Symptomatic Patients

Surgery is indicated for ALL symptomatic patients with severe primary MR regardless of left ventricular function. 1, 3

• Mitral valve repair is strongly preferred over replacement when anatomically feasible, as it reduces mortality by approximately 70% 1
• Surgery must be performed at high-volume heart valve centers with documented repair rates >90% for isolated posterior leaflet prolapse and operative mortality <1% 2

Asymptomatic Patients

Surgery is indicated when ANY of the following thresholds are met: 1, 3

• LVEF ≤60% (critical threshold—do not delay once this is reached)
• LV end-systolic diameter ≥40 mm
• New-onset atrial fibrillation
• Pulmonary artery systolic pressure >50 mmHg

Transcatheter Edge-to-Edge Repair (TEER)

TEER is reserved ONLY for high surgical risk patients with suitable valve morphology who have prohibitive surgical risk—it is NOT first-line therapy for primary MR in surgical candidates. 1, 2

• Favorable anatomy for TEER includes: flail posterior middle scallop, diastolic mitral area >4.0 cm², and absence of severe mitral annular calcification 4

Management of Secondary (Functional) MR

Mandatory First-Line: Guideline-Directed Medical Therapy (GDMT)

GDMT is the mandatory first-line treatment for ALL patients with secondary MR and must be maximized before considering any intervention. 1, 2, 5

GDMT includes: 1, 2

• ACE inhibitors or ARBs as first-line therapy
• Beta-blockers to prevent LV deterioration and improve survival 6
• Mineralocorticoid receptor antagonists
• Diuretics for fluid overload manifestations such as lower extremity edema 1, 3
• Nitrates for acute dyspnea in patients with a large dynamic component of MR 1, 3

Rapid medication titration protocols reduce heart failure hospitalization and facilitate earlier referral for device therapy. 5

Cardiac Resynchronization Therapy (CRT)

CRT should be implemented in patients who meet guideline-directed criteria (typically LVEF ≤35%, QRS ≥150 ms, LBBB), as it may reduce MR severity through increased closing force and resynchronization of papillary muscles. 1, 2, 5

Pursuit of Sinus Rhythm

Management of atrial fibrillation has been shown to significantly reduce mitral regurgitation severity and should be pursued aggressively. 5

Transcatheter Edge-to-Edge Repair (TEER) for Secondary MR

TEER should be considered for patients with severe secondary MR, LVEF 20-50%, persistent NYHA class II-IV symptoms despite optimal medical therapy and CRT when indicated. 1, 2

• Number needed to treat is 3.1 to reduce heart failure hospitalization and 5.9 to reduce all-cause death 5

Surgical Intervention

Surgery is indicated when severe secondary MR is present AND the patient is undergoing coronary artery bypass grafting (CABG) with LVEF >30%. 1, 3

Surveillance and Follow-up Intervals

Asymptomatic severe MR requires clinical and echocardiographic follow-up every 6-12 months. 1, 3, 2

Moderate MR requires clinical evaluation every 6-12 months with annual echocardiography. 1, 3, 2

Mild MR should be monitored every 3-5 years. 1, 3, 2

Serum biomarkers (e.g., BNP) may help guide optimal timing of intervention in asymptomatic patients with severe MR. 1, 3

Multidisciplinary Heart Team Approach

All intervention decisions MUST involve multidisciplinary team (MDT) discussion by the heart team. 1, 2

The heart team must consider: 4, 1

• Valve morphology and MR etiology
• Patient comorbidities and surgical risk
• Frailty and organ system compromise
• Procedure-specific impediments

Input from a cardiologist with experience managing heart failure is essential for secondary MR decisions. 1, 2

Critical Pitfalls to Avoid

Do NOT delay surgery in asymptomatic primary MR once LVEF falls to ≤60% or LVESD reaches ≥40 mm—waiting beyond these thresholds leads to irreversible myopathic changes. 1, 7

Do NOT proceed to intervention for secondary MR without first optimizing GDMT and considering CRT—this is a mandatory prerequisite. 1, 2

Do NOT perform mitral valve replacement when repair is feasible—repair provides superior outcomes. 1

Do NOT use TEER as first-line therapy for primary MR in surgical candidates—surgery remains the gold standard. 1, 2

Do NOT allow patients with severe primary MR to be lost to follow-up—over 50% of patients who do not receive surgery had at least one indication based on current guidelines but were not addressed by the treating physician. 8