Treatment of Severe Mitral Regurgitation

Initial Classification and Management

The American College of Cardiology recommends surgical mitral valve repair as the definitive treatment of choice for both symptomatic patients and asymptomatic patients with left ventricular dysfunction (LVEF ≤60% or LVESD ≥40 mm), with repair strongly preferred over replacement to reduce mortality by approximately 70% 1, 2
The European Heart Journal suggests that primary MR involves structural valve abnormalities (prolapse, flail leaflet, chordal rupture) 1
Secondary MR results from LV dysfunction with structurally normal leaflets, according to the European Heart Journal 3
Transthoracic echocardiography is the fundamental diagnostic tool to distinguish between primary and secondary MR, as stated by the European Heart Journal 4, 5

The European Heart Journal states that severe MR requires integration of multiple echocardiographic parameters, including vena contracta ≥7 mm 1, EROA ≥0.4 cm² (primary MR) or ≥0.3 cm² (secondary MR if elliptical orifice) 1, 2, regurgitant fraction ≥50% 2, regurgitant volume ≥60 mL/beat (primary) or ≥30 mL/beat (secondary) 4, and pulmonary vein systolic flow reversal 4, 5

The Journal of the American College of Cardiology recommends surgery for ALL symptomatic patients with severe primary MR, regardless of left ventricular function, which is a Class I recommendation across all major guidelines 4, 6, 1, 7
Asymptomatic patients should undergo surgery when LVEF ≤60%, LVESD ≥40 mm, new-onset atrial fibrillation, or pulmonary artery systolic pressure >50 mmHg, as suggested by the European Heart Journal and Praxis Medical Insights 4, 5, 7, 1
Mitral valve repair is strongly preferred over replacement when anatomically feasible, reducing mortality by approximately 70% compared to medical management, according to Praxis Medical Insights 2, 1

The European Heart Journal states that guideline-directed medical therapy (GDMT) is mandatory as the first step before considering any intervention for secondary MR 3, 1, 7, 2
GDMT includes ACE inhibitors/ARBs or sacubitril/valsartan, beta-blockers, mineralocorticoid receptor antagonists, SGLT2 inhibitors, diuretics, and nitrates, as recommended by Praxis Medical Insights 1, 2
Cardiac Resynchronization Therapy (CRT) should be implemented in patients meeting guideline criteria, as it may reduce MR severity through improved papillary muscle synchronization, according to Praxis Medical Insights 1, 2
Surgery is indicated when patient is undergoing CABG AND has LVEF >30% (Class I recommendation), or when patient remains symptomatic despite optimal GDMT and has low surgical risk (Class IIb), as stated by the European Heart Journal and Praxis Medical Insights 3, 1, 2, 6

The European Heart Journal recommends clinical and echocardiographic evaluation every 6-12 months for asymptomatic patients with severe MR, and consideration of BNP monitoring to guide timing of intervention 1, 7, 2
Annual echocardiography is recommended for patients with moderate MR, and monitoring every 3-5 years for patients with mild MR, as suggested by Praxis Medical Insights 7, 2, 1

Transesophageal echocardiography (TOE) is indicated when TTE is non-diagnostic, for pre-surgical planning, intraoperative imaging, and post-intervention assessment, according to the European Heart Journal 4, 5
Cardiac MRI should be used when echocardiographic measurements are ambiguous, particularly for quantifying LV/RV function and MR severity, as recommended by Praxis Medical Insights 1, 2
Exercise echocardiography or stress testing should be performed in asymptomatic patients to unmask symptoms or assess dynamic worsening of MR, as stated by the European Heart Journal and Praxis Medical Insights 4, 5, 1