What are the treatment recommendations for mitral regurgitation (MR)?

Treatment Recommendations for Mitral Regurgitation

For severe primary MR, surgery is indicated for all symptomatic patients regardless of left ventricular function, and for asymptomatic patients when LVEF ≤60% or LVESD ≥40 mm, with mitral valve repair strongly preferred over replacement. 1, 2

Primary Mitral Regurgitation Management

Symptomatic Patients

• Surgical intervention is indicated for all symptomatic patients with severe primary MR, irrespective of LV systolic function 1, 2
• Mitral valve repair is unanimously preferred over replacement when a durable repair can be achieved 1, 2
• Surgery should be performed at heart valve centers with high repair rates (≥80-90%) 2

Asymptomatic Patients

Surgery is indicated when:

• LVEF ≤60% and/or LVESD ≥40 mm 1, 2
• New-onset atrial fibrillation develops 1
• Pulmonary artery systolic pressure >50 mmHg 1
• Progressive LV dilatation or declining ejection fraction on serial imaging 1

Surgery may be considered when LVEF >60% and LVESD <40 mm if:

• LA volume index ≥60 mL/m² with low procedural risk at an experienced center 1
• Successful and durable repair is highly likely 1

Transcatheter Options for Primary MR

• TEER may be considered as an alternative to surgery only in symptomatic patients with severe primary MR who are at high/prohibitive surgical risk 1
• Both ACC/AHA and ESC guidelines agree on this indication, though with different recommendation classes 1

Secondary Mitral Regurgitation Management

Medical Therapy First-Line

• Guideline-directed medical therapy (GDMT) is mandatory as the initial treatment for all patients with secondary MR 2
• GDMT includes ACE inhibitors/ARBs, beta-blockers, and mineralocorticoid receptor antagonists 2
• Cardiac resynchronization therapy should be implemented if indicated 1

Surgical Intervention

MV surgery (repair or replacement) is reasonable when:

• Patients remain symptomatic despite optimal GDMT 1
• Concomitant CABG is indicated 1
• Low surgical risk with appropriate anatomy, regardless of LV dysfunction level 1

Transcatheter Edge-to-Edge Repair (TEER)

TEER should be considered for patients with:

• Severe secondary MR with appropriate anatomy fulfilling COAPT criteria 1
• LVEF 20%-50%, LVESD ≤70 mm, SPAP ≤70 mm Hg 1
• Persistent symptoms despite optimal GDMT 1, 2
• LVEF >30% with no indication for coronary revascularization 2

Important caveat: Both ACC/AHA and ESC guidelines emphasize that the best therapy for chronic secondary MR is unclear because MR is only one component of the disease, and restoration of MV competence is not curative 1

Severity Thresholds for Intervention

Severe MR is defined by:

• Vena contracta ≥7 mm 1, 2
• EROA ≥0.4 cm² for primary MR 1, 2
• EROA ≥0.2-0.3 cm² for secondary MR (lower threshold due to elliptical orifice) 1, 2
• Regurgitant volume ≥60 mL/beat for primary MR 1, 2
• Regurgitant volume ≥30 mL/beat for secondary MR 1
• Regurgitant fraction ≥50% 1
• Pulmonary vein systolic flow reversal 1

Surveillance Protocols

For asymptomatic severe MR:

• Clinical and echocardiographic follow-up every 6-12 months 1, 2
• Consider biomarkers (BNP) and novel LV function measurements like global longitudinal strain 1, 2
• Exercise echocardiography to unmask symptoms in asymptomatic patients 1, 2

For asymptomatic moderate MR:

• Follow-up every 1-2 years 1

Acute Severe MR

Urgent surgical intervention may be necessary 1

• Vasodilator therapy for hemodynamic stabilization 2
• Inotropic support if hemodynamically unstable 2
• Intra-aortic balloon pump for mechanical support if needed 2

Critical Decision-Making Pitfalls

Avoid vasodilators in specific contexts: In patients with hypertrophic cardiomyopathy or mitral valve prolapse, vasodilators can paradoxically increase MR severity 3

Heart team evaluation is essential: All therapeutic decisions for secondary MR should involve multidisciplinary heart team discussion given the complexity and limited evidence base 1

Risk stratification must be comprehensive: Assessment should include STS-PROM score, frailty, organ system compromise, and procedure-specific impediments before determining surgical candidacy 2