What is the treatment for mitral regurgitation?

Treatment of Mitral Regurgitation

The treatment of mitral regurgitation should focus on optimizing medical therapy for heart failure while planning for appropriate surgical or transcatheter intervention based on MR etiology, severity, and patient characteristics. 1

Classification and Evaluation

• Primary (degenerative) MR: Direct valve abnormality
• Secondary (functional) MR: Dysfunction of surrounding structures (LV dilation, papillary muscle displacement)

Diagnostic Assessment

• Echocardiography is essential for determining:
  • MR severity
  • LV size and function
  • LA size
  • Pulmonary artery pressure
  • Valve anatomy and repair feasibility 1
• Cardiac MRI when echocardiographic measurements are ambiguous 1
• Exercise testing to unmask symptoms in apparently asymptomatic patients 1

Treatment Algorithm

1. Medical Therapy

For Primary MR:

• Limited evidence for medical therapy in asymptomatic patients
• β-blockers may lessen MR, prevent LV deterioration, and improve survival in asymptomatic patients with moderate to severe primary MR 2
• ACE inhibitors/ARBs may reduce MR in asymptomatic patients 2
• Caution: Vasodilators can increase MR severity in hypertrophic cardiomyopathy or mitral valve prolapse 2

For Secondary MR:

• Optimize guideline-directed medical therapy (GDMT):
  • ACE inhibitors/ARBs
  • Beta-blockers
  • Mineralocorticoid receptor antagonists
  • SGLT2 inhibitors
  • Sacubitril/valsartan 3, 1
• Consider cardiac resynchronization therapy (CRT) if indicated 3, 1

2. Surgical Intervention

Primary MR - Indications for Surgery:

• Symptomatic patients with severe MR and LVEF >30% 3
• Asymptomatic patients with severe MR and:
  • LVEF ≤60% or LVESD ≥40 mm 1
  • New-onset atrial fibrillation 1
  • Pulmonary hypertension (PASP ≥50 mmHg) 1
  • High likelihood of successful repair (>95%) with low mortality risk (<1%) 1

Secondary MR - Indications for Surgery:

• Severe MR in patients undergoing CABG 3
• Moderate-to-severe MR in patients undergoing CABG (reasonable) 3
• Persistent symptoms despite optimal GDMT and CRT (if indicated) 3

3. Transcatheter Interventions

Transcatheter Edge-to-Edge Repair (TEER):

Primary MR:

• Consider for severely symptomatic (NYHA class III/IV) patients with high/prohibitive surgical risk 3

Secondary MR:

• Should be considered in patients with LVEF >30% and severe MR who have no indication for coronary revascularization after GDMT (including CRT if indicated) 3
• Reasonable for patients with appropriate anatomy, LVEF <50%, and persistent symptoms despite GDMT 3
• May be considered in selected cases of end-stage heart failure after evaluation for ventricular assist device or heart transplant 3

Common Pitfalls to Avoid

1. Delaying intervention until symptoms are severe or LV dysfunction is irreversible 1
2. Inadequate assessment of MR severity leading to incorrect treatment decisions 1
3. Failure to optimize medical therapy before considering intervention for secondary MR 1
4. Not referring patients to experienced centers with high repair rates (≥80-90%) 1, 4

Outcomes

• Untreated severe organic MR has approximately 6% yearly mortality rate in patients aged 50 years or older 4
• Valve repair improves outcomes compared to valve replacement, reducing mortality by about 70% in severe organic MR 4
• Transcatheter leaflet repair is associated with significantly reduced 24-month mortality compared to medical therapy alone in secondary MR 5

The best outcomes are achieved when patients are referred early to centers with expertise in mitral valve repair, particularly for asymptomatic patients with severe MR 1, 4.