What is the initial management for a patient with symptomatic mitral stenosis?

Management of Symptomatic Mitral Stenosis

For symptomatic patients with severe mitral stenosis (valve area <1.5 cm²), percutaneous mitral commissurotomy (PMC) is the first-line treatment when valve anatomy is favorable, while surgical valve replacement is indicated for those with unfavorable anatomy or contraindications to PMC. 1, 2

Initial Assessment Before Treatment

Before any intervention, you must:

• Confirm severity with echocardiography showing mitral valve area <1.5 cm² and assess valve morphology using scoring systems (echocardiographic score ≤8 predicts PMC success) 1, 2
• Perform transesophageal echocardiography to exclude left atrial thrombus, which is an absolute contraindication to PMC 1, 2, 3
• Evaluate anatomical features including valve calcification, subvalvular apparatus integrity, and presence/severity of mitral regurgitation 1, 2

Treatment Algorithm by Valve Anatomy

Favorable Anatomy (Class I Recommendation)

PMC is indicated for all symptomatic patients with favorable characteristics, defined as: 1, 2

• Echocardiographic score ≤8 1
• Minimal to mild valve calcification 1
• Preserved subvalvular apparatus 1
• Absence of severe mitral regurgitation 1
• No left atrial thrombus 1

Unfavorable Anatomy

PMC should be considered as initial treatment even with suboptimal anatomy if patients have mild-to-moderate calcification with otherwise favorable clinical characteristics (younger age, no prior commissurotomy, NYHA class <IV, no severe pulmonary hypertension) 1, 2

Surgery (mostly valve replacement) is indicated for patients with: 1, 2

• Severe calcification 1
• Extensive subvalvular disease 1
• Significant mitral regurgitation 1
• Persistent left atrial thrombus despite 1-3 months of anticoagulation 1

High Surgical Risk Patients

PMC can be attempted as palliative therapy even with suboptimal anatomy in elderly patients where surgery carries prohibitive risk 2

Medical Therapy (Symptom Control Only)

Medical management does not prevent disease progression and should never replace definitive intervention when indicated, but provides temporary symptom relief: 2, 4, 3

Heart Rate Control

• Beta-blockers are first-line for rate control, particularly critical in atrial fibrillation 4, 3
• Non-dihydropyridine calcium channel blockers (diltiazem, verapamil) are effective alternatives 1, 4, 3
• Digoxin is specifically recommended for heart rate control in patients with atrial fibrillation and mitral stenosis 1, 4, 3

Diuretics

• Diuretics relieve pulmonary congestion and peripheral edema but do not alter disease trajectory 1, 2, 4, 3

Anticoagulation (Mandatory in Specific Situations)

Vitamin K antagonists (warfarin) with target INR 2.0-3.0 are indicated for: 1, 4, 3, 5

• New-onset or paroxysmal atrial fibrillation 1, 5
• History of systemic embolism 1, 4, 5
• Left atrial thrombus 1, 4
• Dense spontaneous contrast on transesophageal echocardiography 1, 4
• Enlarged left atrium (M-mode diameter >50 mm or volume >60 mL/m²) 1, 4

Indications for Urgent Intervention in Symptomatic Patients

Immediate cardiology referral for intervention is required when: 2, 3

• Symptomatic severe mitral stenosis (valve area <1.5 cm²) with dyspnea, fatigue, or pulmonary congestion 2, 3
• Pulmonary artery systolic pressure >50 mmHg at rest 1, 2, 3
• New-onset atrial fibrillation in severe mitral stenosis 1, 3
• Need for major non-cardiac surgery in patients with severe mitral stenosis 1, 3
• Desire for pregnancy in women with severe mitral stenosis 1, 3

Special Populations

Pregnancy

In pregnant women with moderate-to-severe mitral stenosis, PMC should be performed before conception or during pregnancy with appropriate precautions, as >50% of previously asymptomatic women will develop heart failure during pregnancy 1, 2

High Thromboembolic Risk

PMC should be considered in asymptomatic patients with high thromboembolic risk (history of systemic embolism, dense spontaneous contrast, new-onset atrial fibrillation) who have favorable anatomy 1, 4

Critical Pitfalls to Avoid

• Never delay intervention in symptomatic patients with severe mitral stenosis, as this leads to irreversible pulmonary hypertension, right heart failure, and increased mortality 2, 3
• Never use direct oral anticoagulants (DOACs) instead of warfarin in mitral stenosis patients with atrial fibrillation—vitamin K antagonists are mandatory 1, 4, 3
• Never attempt cardioversion before intervention in patients with severe mitral stenosis and persistent atrial fibrillation, as it does not durably restore sinus rhythm 1, 3
• Never proceed with PMC without transesophageal echocardiography to exclude left atrial thrombus 1, 2, 3
• Never treat symptomatic severe mitral stenosis with medical therapy alone for extended periods, as this is purely palliative and allows disease progression 2, 4, 3

Follow-Up Strategy

After successful PMC, patients require yearly clinical and echocardiographic assessment to detect restenosis 2

Symptomatic patients on medical therapy awaiting intervention require more frequent monitoring with clinical assessment and echocardiography 3