Management of Mitral Regurgitation

Initial Classification and Assessment

The American College of Cardiology recommends that echocardiography is essential to determine whether MR is primary or secondary, as this distinction completely changes the management algorithm 1, 2
Severe MR is defined by vena contracta ≥7 mm, EROA ≥0.4 cm² for primary MR, regurgitant fraction ≥50%, and regurgitant volume ≥60 mL/beat 1, 2
For secondary MR, the threshold may be lower at EROA ≥0.3 cm² if the regurgitant orifice is elliptical 3, 1
The European Heart Journal suggests using cardiovascular magnetic resonance (CMR) when echocardiographic measurements are ambiguous or uncertain 3, 1
Exercise echocardiography should be performed in patients with exercise-induced symptoms to assess dynamic worsening of MR 1, 2

The American College of Cardiology indicates that surgery is indicated for all symptomatic patients with severe primary MR regardless of left ventricular function 4, 1, 2
Mitral valve repair is strongly preferred over replacement when anatomically feasible, as it reduces mortality by approximately 70% 4
Surgery should be performed at a heart valve center with high repair rates and low operative mortality 3
The American College of Cardiology recommends that surgery is indicated when LVEF ≤60% and/or LV end-systolic diameter ≥40 mm 4, 1
Transcatheter edge-to-edge repair (TEER) is reserved only for high surgical risk patients with suitable valve morphology who have prohibitive surgical risk 4, 3

Guideline-directed medical therapy (GDMT) is the mandatory first-line treatment for all patients with secondary MR 1, 2
GDMT includes ACE inhibitors/ARBs, beta-blockers, and mineralocorticoid receptor antagonists 1, 2
Diuretics are first-line for fluid overload manifestations such as lower extremity edema 2
Nitrates may be useful for acute dyspnea in patients with a large dynamic component of MR 2
The American College of Cardiology suggests that cardiac resynchronization therapy (CRT) should be implemented in patients who meet guideline-directed criteria 4, 2
TEER should be considered for patients with severe secondary MR, LVEF 20-50%, persistent NYHA class II-IV symptoms despite optimal medical therapy 4, 1
Surgery is indicated when severe secondary MR is present and the patient is undergoing coronary artery bypass grafting (CABG) with LVEF >30% 3, 2

Asymptomatic patients with severe MR require clinical and echocardiographic follow-up every 6-12 months 1, 2
Patients with moderate MR should have clinical evaluation every 6-12 months with annual echocardiography 2
Patients with mild MR should be monitored every 3-5 years 2
Serum biomarkers (e.g., BNP) may help guide optimal timing of intervention in asymptomatic patients with severe MR 3, 1, 2

All intervention decisions should involve multidisciplinary team (MDT) discussion by the heart team 4, 2
The heart team should consider valve morphology, MR etiology, patient comorbidities, surgical risk, frailty, organ system compromise, and procedure-specific impediments 1, 2
Input from a cardiologist with experience managing heart failure and MR is essential for secondary MR decisions 4

Do not delay surgery in asymptomatic primary MR once LVEF falls to ≤60% or LVESD reaches ≥40 mm 4
Do not proceed to intervention for secondary MR without first optimizing GDMT and considering CRT 4
Do not perform mitral valve replacement when repair is feasible 4
Do not use TEER as first-line therapy for primary MR in surgical candidates 4, 3

Favorable anatomy for TEER includes flail posterior middle scallop, diastolic mitral area >4.0 cm², and absence of severe mitral annular calcification, as recommended by the American College of Cardiology 5