What is the management strategy for a patient with symptomatic mitral stenosis, possibly with a history of atrial fibrillation or rheumatic fever?

Management of Symptomatic Mitral Stenosis

For symptomatic patients with severe mitral stenosis (valve area <1.5 cm²), percutaneous mitral commissurotomy (PMC) is the treatment of choice when valve anatomy is favorable, as it provides definitive relief and prevents progression to irreversible pulmonary hypertension and death. 1, 2

Initial Assessment and Severity Classification

Echocardiography is the diagnostic method of choice for evaluating mitral stenosis severity and hemodynamic consequences. 1

Severe Mitral Stenosis is Defined By:

• Mitral valve area ≤1.5 cm² (measured by planimetry) 1
• Mean transmitral gradient ≥10 mmHg 1
• Diastolic pressure half-time ≥150 ms 1

Critical Pre-Intervention Evaluation:

• Transesophageal echocardiography (TOE) must be performed to exclude left atrial thrombus before any intervention 1, 2
• Valve morphology scoring (Wilkins score) determines suitability for PMC: scores <8 predict excellent outcomes, while scores >10 suggest need for surgical replacement 3
• Stress testing should be performed if symptoms are equivocal or discordant with stenosis severity 1

Intervention Strategy for Symptomatic Patients

First-Line Treatment: Percutaneous Mitral Commissurotomy (PMC)

PMC is indicated (Class I recommendation) for all symptomatic patients (NYHA class II-IV) with severe mitral stenosis and favorable valve anatomy. 1, 2, 4

Favorable characteristics for PMC include:

• Wilkins score <8 3
• Absence of left atrial thrombus 1
• Less than moderate mitral regurgitation 1
• Minimal valve calcification 1
• Elastic, symmetric commissures 3

PMC should be considered as initial treatment even in patients with suboptimal anatomy (mild to moderate calcification or impaired subvalvular apparatus) if they have favorable clinical characteristics and no contraindications. 1

Surgical Intervention

Surgery (valve replacement or open commissurotomy) is indicated when: 1, 2

• PMC is contraindicated or anatomically unsuitable (heavy calcification, Wilkins score >10, severe subvalvular disease) 1, 3
• Moderate to severe mitral regurgitation is present 1
• Left atrial thrombus persists after 1-3 months of anticoagulation 1
• Previous PMC has failed 1

Open surgical commissurotomy may be preferred by experienced surgical teams in young patients with mild to moderate mitral regurgitation. 1

Management of Atrial Fibrillation

Atrial fibrillation is a critical complication that worsens hemodynamic tolerance, markedly increases thromboembolic risk, and negatively impacts outcomes after commissurotomy. 5

Rate Control:

• Beta-blockers, calcium channel blockers, or digoxin should be used for heart rate control in patients with atrial fibrillation 1, 4
• Maintaining adequate rate control is essential to prevent pulmonary congestion 2

Anticoagulation - Critical Mandate:

Vitamin K antagonist (warfarin) anticoagulation with target INR 2.0-3.0 is mandatory for all patients with mitral stenosis and atrial fibrillation, regardless of CHA₂DS₂-VASc score. 1, 4, 6, 5

Anticoagulation is also indicated in patients with mitral stenosis who have: 2, 4

• History of systemic embolism
• Dense spontaneous contrast in the left atrium
• Left atrial thrombus
• Significantly enlarged left atrium (>60 mL/m²)
• New-onset atrial fibrillation

Critical caveat: NOACs (novel oral anticoagulants) are NOT recommended in moderate-to-severe mitral stenosis due to lack of safety data; only vitamin K antagonists should be used. 4, 5

High-Risk Situations Requiring Urgent Intervention

Even asymptomatic patients require intervention when high-risk features are present: 1, 2

High Thromboembolic Risk:

• History of systemic embolism 1
• Dense spontaneous contrast in left atrium 1, 2
• New-onset atrial fibrillation 1, 2

High Risk of Hemodynamic Decompensation:

• Pulmonary artery systolic pressure >50 mmHg at rest 1, 2
• Need for major non-cardiac surgery 1, 2
• Desire for pregnancy 1, 2

Medical Management (Purely Palliative)

Medical therapy does not prevent disease progression and serves only for symptom relief. 4

Symptomatic Relief:

• Diuretics for pulmonary congestion or edema 1, 4
• Heart rate control agents (beta-blockers, calcium channel blockers, digoxin) for symptom relief, particularly with atrial fibrillation 1, 4

Prognosis Without Intervention

Symptomatic patients with severe mitral stenosis have dismal prognosis without intervention, with 0-15% 10-year survival rate, particularly when intervention is contraindicated or high-risk. 7 Delays in intervention can lead to irreversible pulmonary hypertension, right heart failure, and death. 2

Common Pitfalls and Caveats

• Never delay cardiology referral for symptomatic severe mitral stenosis—this is a time-sensitive condition where delays cause irreversible complications 2
• Always exclude left atrial thrombus with TOE before any intervention; presence of thrombus is an absolute contraindication to PMC until resolved 1
• Do not use NOACs in patients with moderate-to-severe mitral stenosis—only warfarin is appropriate 4, 5
• Medical therapy alone is inadequate—it provides only temporary symptom relief without preventing progression 4
• Patients may unconsciously reduce activity to avoid symptoms, leading to underestimation of disease severity; specific questioning about exercise capacity is essential 8