What is the management approach for mitral stenosis?

Management of Mitral Stenosis

For symptomatic severe mitral stenosis with rheumatic etiology and favorable valve morphology, percutaneous mitral balloon commissurotomy (PMBC) is the first-line intervention, while degenerative mitral stenosis requires medical management with heart rate control and diuretics, reserving surgery for severely symptomatic patients. 1, 2, 3

Distinguish Etiology First

The critical first step is determining whether the stenosis is rheumatic (RMS) or degenerative (DMS), as this fundamentally changes management:

• Rheumatic MS shows commissural fusion with valve doming on imaging, making it amenable to PMBC 3
• Degenerative MS presents with funnel-like stenosis from mitral annular calcification without commissural fusion, rendering PMBC ineffective 3, 4
• DMS typically occurs in elderly patients with multiple comorbidities who are high surgical risk 5

Medical Management

Medical therapy is palliative and does not prevent disease progression, but provides symptom relief 2:

Heart Rate Control

• Beta-blockers or rate-limiting calcium channel blockers are the cornerstone for controlling heart rate, particularly crucial in atrial fibrillation to prolong diastolic filling time 2, 3
• Digoxin is specifically recommended for heart rate control in patients with atrial fibrillation 2, 6
• Ivabradine may be considered when beta-blockers are contraindicated (e.g., reactive airway disease), though this is based on limited evidence 7

Symptom Relief

• Diuretics should be used when pulmonary congestion or peripheral edema is present 2, 6, 3

Anticoagulation (Mandatory in Specific Situations)

Vitamin K antagonists (target INR 2-3) are indicated for 2, 6, 3:

• Atrial fibrillation (any type)
• History of systemic embolism
• Dense spontaneous contrast in left atrium on echocardiography
• Enlarged left atrium (M-mode diameter >60 mL/m²)

Critical caveat: NOACs should NOT be used in mitral stenosis patients with atrial fibrillation—only vitamin K antagonists 2

Intervention Indications

Symptomatic Severe MS (MVA ≤1.5 cm²)

PMBC is indicated for all symptomatic patients (NYHA class II-IV) with favorable valve morphology 2, 6, 3:

• Minimal valve calcification
• No significant mitral regurgitation
• Preserved subvalvular apparatus

Asymptomatic Severe MS

Intervention should be considered when 1, 2, 6:

• Pulmonary artery systolic pressure >50 mmHg
• New-onset atrial fibrillation
• High thromboembolic risk (history of embolism or dense spontaneous contrast)
• Pregnancy is desired or planned

Surgery Indications

Mitral valve surgery is reserved for 1, 3:

• Degenerative MS with severe symptoms unresponsive to medical therapy
• Unfavorable valve morphology for PMBC (heavy calcification, significant subvalvular fusion)
• Concurrent significant mitral regurgitation
• Failed previous PMBC

Surgery should be performed at specialized heart valve centers to ensure optimal outcomes 1

Special Populations

Pregnancy

• PMBC should be evaluated in all pregnant patients with severe MS, as >50% of previously asymptomatic women will develop heart failure during pregnancy 1
• PMBC can be performed relatively safely in symptomatic patients (NYHA III-IV) despite medical therapy during pregnancy 3
• Mitral valve surgery carries significant risk to mother and fetus, reserved only when the mother's life is at immediate risk 3
• Even mild MS may be poorly tolerated due to increased heart rate and stroke volume of pregnancy 1

Degenerative MS

• Medical management is first-line therapy with heart rate control using beta-blockers to lengthen diastole and improve left ventricular filling 1
• Surgery should only be considered when symptoms are severely limiting and unmanageable with medical therapy 5
• Transcatheter mitral valve replacement may become a future option for these high-risk surgical candidates 4

Monitoring and Follow-up

Asymptomatic Severe MS (MVA ≤1.0 cm²)

• Follow-up with echocardiography every 2-3 years per European Society of Cardiology 2, 6
• Follow-up every 3-5 years per American College of Cardiology/American Heart Association 2
• More frequent monitoring (yearly) for patients with very severe stenosis or borderline hemodynamics 6

Post-PMBC Monitoring

Key parameters determining long-term outcomes 3:

• Mitral valve area achieved
• Residual mitral regurgitation severity
• Mean transmitral gradient
• Pulmonary artery pressure

Diagnostic Workup

Essential Imaging

• Transthoracic echocardiography (TTE) is the preferred initial technique for diagnosis and severity assessment 1
• Transesophageal echocardiography (TOE) is indicated to 1:
  • Exclude left atrial thrombus before PMBC
  • Evaluate presence and severity of concurrent mitral regurgitation
  • Clarify severity when TTE images are technically limited
  • Provide detailed mitral anatomy before intervention

When Symptoms Don't Match Severity

• Exercise stress echocardiography is reasonable when there is discrepancy between clinical symptoms and echocardiographic severity 1
• Stress testing is particularly important when MVA >1.5 cm² to unveil hemodynamic effects 1
• Right heart catheterization may clarify valve lesion severity when echocardiographic data are inconclusive 1

Critical Pitfalls to Avoid

• Never use NOACs in mitral stenosis patients with atrial fibrillation—only vitamin K antagonists are appropriate 2
• Do not rely solely on pressure half-time method for MVA calculation in mixed valvular disease (MS with AR or MR), as measurements can be confounded 1
• Medical therapy alone does not prevent disease progression—regular monitoring for development of intervention indications is essential 2
• Do not delay intervention in pregnant patients with severe MS, as maternal and fetal outcomes worsen significantly 1, 3