What are the symptoms and treatment options for Mitral (mitral valve) stenosis?

Symptoms and Treatment of Mitral Stenosis

Mitral stenosis typically presents with exertional dyspnea, fatigue, hemoptysis, and symptoms of heart failure, and the treatment of choice for symptomatic patients with favorable valve anatomy is percutaneous mitral commissurotomy (PMC), while valve replacement is indicated for unfavorable valve anatomy or when PMC is contraindicated. 1

Clinical Presentation

Cardinal Symptoms

• Dyspnea on exertion - The most common initial symptom
• Fatigue - Due to decreased cardiac output
• Orthopnea and paroxysmal nocturnal dyspnea - As disease progresses
• Hemoptysis - Due to rupture of pulmonary-bronchial venous connections
• Palpitations - Often related to atrial fibrillation
• Chest pain - Less common than in other valvular diseases
• Systemic embolism - Particularly in patients with atrial fibrillation

Physical Examination Findings

• Loud S1
• Opening snap following S2
• Mid-diastolic rumbling murmur
• Signs of pulmonary hypertension in advanced cases
• Irregular pulse if atrial fibrillation is present

Diagnostic Approach

Echocardiography

• Transthoracic echocardiography (TTE) - Primary diagnostic tool 1
• Key measurements:
  • Valve area ≤1.0 cm² indicates severe stenosis
  • Diastolic pressure half-time ≥150 ms
  • Mean transmitral pressure gradient ≥10 mmHg
  • Left atrial enlargement

Additional Testing

• Transesophageal echocardiography (TOE) - To exclude left atrial thrombus before intervention 1
• Exercise testing - To unmask symptoms in apparently asymptomatic patients

Treatment Algorithm

Medical Management

1. Rate control for patients in atrial fibrillation

   • Beta blockers or calcium channel blockers 1
   • Beta-1 selective blockers for patients in sinus rhythm

2. Anticoagulation

   • Vitamin K antagonists (target INR 2-3) for:
     • Patients with atrial fibrillation
     • Prior embolic events
     • Left atrial thrombus 1

3. Diuretics - For symptom relief in fluid overload

Interventional Management

For Rheumatic Mitral Stenosis:

1. Percutaneous Mitral Commissurotomy (PMC)

   • First-line intervention for symptomatic patients with favorable valve anatomy 1
   • Indicated for:
     • Symptomatic patients with MVA ≤1.5 cm²
     • Asymptomatic patients with high-risk features

2. Surgical Options (when PMC is contraindicated or unsuccessful)

   • Mitral valve repair - When feasible
   • Mitral valve replacement - When repair is not possible

For Degenerative Mitral Stenosis:

1. Valve replacement - Only option for severe cases without commissural fusion 2, 1

2. Transcatheter valve implantation - May be considered in elderly inoperable patients with severely calcified mitral annulus 2, 1

Special Considerations

Pregnancy

• Severe asymptomatic mitral stenosis should be treated before pregnancy
• PMC should be performed in pregnant women with NYHA III-IV symptoms despite medical therapy 1

Elderly Patients

• PMC can be a useful palliative option in high-risk elderly patients with rheumatic mitral stenosis 2
• For elderly patients with degenerative mitral stenosis and severely calcified annulus, transcatheter valve implantation may be considered if inoperable 2, 1

Combined Valve Disease

• In patients with severe mitral stenosis and severe aortic valve disease, surgery is preferable when not contraindicated 2
• With moderate aortic valve disease, PMC can postpone surgical treatment of both valves 2

Pitfalls and Caveats

1. Avoid delaying intervention in symptomatic patients as this leads to worse outcomes 1

2. Do not attempt cardioversion before intervention in patients with severe mitral stenosis and atrial fibrillation, as sinus rhythm is unlikely to be maintained 1

3. Recognize the difference between rheumatic and degenerative mitral stenosis:

   • Rheumatic MS has commissural fusion amenable to PMC
   • Degenerative MS has calcification without commissural fusion, making PMC ineffective 2, 3, 4

4. Carefully assess valve morphology before deciding on intervention type, as unfavorable anatomy significantly impacts PMC outcomes 2, 1

5. Consider the multifactorial nature of predicting PMC results, beyond just valve anatomy scores 2