What are the treatment guidelines for symptomatic mitral stenosis?

Management of Mitral Stenosis

Symptomatic patients with severe mitral stenosis (valve area <1.5 cm²) require urgent cardiology referral for percutaneous mitral balloon commissurotomy (PMBC), which is the first-line intervention for those with favorable valve morphology. 1

Immediate Assessment and Referral

Determine the etiology first—rheumatic versus degenerative mitral stenosis—because interventions differ fundamentally between these two types. 2

• Rheumatic mitral stenosis has commissural fusion and is amenable to PMBC 2
• Degenerative mitral stenosis lacks commissural fusion, making PMBC ineffective 2, 3

Urgent cardiology referral is mandatory for:

• Any symptomatic patient (NYHA class II-IV) with dyspnea, fatigue, or pulmonary congestion 1
• Pulmonary artery systolic pressure >50 mmHg at rest, even if asymptomatic 1
• New-onset atrial fibrillation or paroxysmal atrial fibrillation 1
• History of systemic embolism or left atrial thrombus 1
• Dense spontaneous contrast in the left atrium on echocardiography 1
• Women desiring pregnancy with severe mitral stenosis 1
• Need for major non-cardiac surgery 1

Delays in referral can lead to irreversible pulmonary hypertension, right heart failure, and death. 1

Medical Management (Palliative Only)

Medical therapy is purely palliative and does not prevent disease progression—it serves only as a bridge to intervention or for patients who cannot undergo intervention. 4, 1

Symptom Control

• Diuretics for pulmonary congestion or peripheral edema when present 4, 2
• Heart rate control is critical, particularly in atrial fibrillation, to prolong diastolic filling time 4, 2

Heart Rate Control Strategy

For patients in sinus rhythm:

• Beta-blockers are first-line (metoprolol showed 90% subjective improvement and greatest exercise capacity improvement) 4, 5
• Calcium channel blockers are second-line 4
• Digoxin is ineffective in sinus rhythm 5

For patients with atrial fibrillation:

• Verapamil or beta-blockers are preferred for rate control 4, 5
• Digoxin can be used specifically for heart rate control in atrial fibrillation 4, 2
• Verapamil showed 80% subjective improvement in atrial fibrillation patients 5

Anticoagulation (Mandatory in Specific Situations)

Use vitamin K antagonists (target INR 2-3), NOT NOACs, for:

• History of systemic embolism 4, 2
• Atrial fibrillation 2
• Dense spontaneous contrast in the left atrium 4, 2
• Enlarged left atrium (M-mode diameter >60 mL/m²) 4

Critical pitfall: Patients with mitral stenosis and atrial fibrillation should be kept on vitamin K antagonists and not receive NOACs. 4

Intervention Indications and Treatment

First-Line Intervention

PMBC is the treatment of choice (Class I indication) for:

• All symptomatic patients with severe mitral stenosis (valve area ≤1.5 cm²) and favorable valve morphology 4, 1, 2
• Rheumatic mitral stenosis with commissural fusion 2

Surgical mitral valve replacement is indicated for:

• Symptomatic patients not suitable for PMBC (unfavorable valve anatomy, significant calcification, major concomitant mitral regurgitation) 1, 6
• Degenerative mitral stenosis where PMBC is ineffective 2, 3

Asymptomatic Patients Requiring Intervention

Intervene in asymptomatic patients when:

• Pulmonary artery systolic pressure >50 mmHg 4, 2
• New-onset atrial fibrillation 4, 2
• High thromboembolic risk (history of embolism, dense spontaneous contrast) 4, 2

Monitoring and Follow-Up

For asymptomatic severe mitral stenosis (MVA ≤1.0 cm²):

• European Society of Cardiology recommends follow-up every 2-3 years 4, 1, 2
• American College of Cardiology/American Heart Association recommends every 3-5 years 4, 2
• Regular echocardiographic assessment is essential to monitor disease progression 4

For asymptomatic patients with clinically significant mitral stenosis:

• American College of Cardiology recommends yearly clinical and echocardiographic examinations 1

Special Populations

Pregnancy:

• PMBC can be performed relatively safely in symptomatic patients (NYHA III-IV) despite medical therapy during pregnancy 2
• Mitral valve surgery carries significant risk to mother and fetus, reserved only when mother's life is at risk 2

Perioperative management for non-cardiac surgery:

• Cardiology referral is mandatory to assess need for balloon mitral valvuloplasty or surgical repair before high-risk non-cardiac surgery 1
• Heart rate control is critical perioperatively to prevent severe pulmonary congestion 1

Post-Intervention Monitoring

Parameters determining long-term outcomes after PMBC:

• Mitral valve area achieved 2
• Residual mitral regurgitation severity 2
• Mean transmitral gradient 2
• Pulmonary artery pressure 2

Critical Pitfalls to Avoid

• Never delay cardiology referral in symptomatic patients—irreversible pulmonary hypertension can develop 1
• Do not rely on medical therapy alone as definitive treatment—it is purely palliative 4, 1
• Do not use NOACs in mitral stenosis patients with atrial fibrillation—only vitamin K antagonists are appropriate 4
• Do not forget to distinguish rheumatic from degenerative etiology—treatment approaches differ fundamentally 2
• Regular monitoring is essential even in asymptomatic patients—watch for development of intervention indications 4