Is balloon valvuloplasty (percutaneous transluminal valvuloplasty) a reasonable treatment option for patients with rheumatic mitral valve stenosis?

Balloon Valvuloplasty for Rheumatic Mitral Stenosis

Balloon valvuloplasty is the first-line treatment for symptomatic patients with moderate to severe rheumatic mitral stenosis who have favorable valve morphology, and it is equally indicated for asymptomatic patients with pulmonary hypertension. 1

Class I Indications (Strongest Recommendations)

Balloon valvuloplasty is definitively indicated in the following scenarios:

• Symptomatic patients (NYHA class II-IV) with moderate to severe rheumatic mitral stenosis (mitral valve area ≤1.5 cm²) who have favorable valve morphology—specifically thickened leaflets with fused commissures—in the absence of left atrial thrombus or moderate to severe mitral regurgitation 1

• Asymptomatic patients with moderate to severe rheumatic mitral stenosis who have pulmonary hypertension (pulmonary artery systolic pressure >50 mm Hg at rest or >60 mm Hg with exercise) and favorable valve morphology, without left atrial thrombus or significant mitral regurgitation 1

• Patients with rheumatic mitral valve restenosis after previous intervention who meet the above criteria 1

Defining Favorable Valve Morphology

The success of balloon valvuloplasty critically depends on valve anatomy:

• Favorable anatomy includes commissural fusion with relatively pliable leaflets, balanced chordal attachments, and minimal calcification 1

• Unfavorable features that predict worse outcomes include heavily calcified valves, parachute mitral valves, supramitral rings, small mitral annulus, and significant subvalvular disease 1

• The Wilkins echocardiographic score (range 0-16) is the standard assessment tool, with scores ≤8 predicting better outcomes 2, 3

Class IIa Indications (Reasonable Alternative)

Balloon valvuloplasty is reasonable in these situations:

• Symptomatic patients with moderate to severe rheumatic mitral stenosis who have calcified valves but are high-risk surgical candidates or not candidates for surgery 1

Expected Outcomes and Durability

The procedure delivers excellent immediate and sustained results:

• Immediate hemodynamic improvement includes mitral valve area increase from approximately 1.0 cm² to 2.0-2.4 cm² and mean gradient reduction from 14-15 mm Hg to 6 mm Hg 4, 2

• Long-term durability shows 5-year event-free survival of 51-60% overall, with significantly better outcomes (70-84% at 5 years) in patients with favorable valve morphology (Wilkins score ≤8) 2, 3

• Very long-term follow-up (median 8.3 years, up to 23 years) demonstrates that more than 75% of patients maintain sustained results without need for repeat intervention 3

• Restenosis rates range from 4-31% depending on valve morphology and follow-up duration, occurring significantly less frequently in patients with favorable anatomy 5, 2

Comparison to Surgical Commissurotomy

Balloon valvuloplasty matches or exceeds surgical outcomes:

• Equivalent hemodynamic results at 3 years compared to open surgical commissurotomy, with mitral valve areas of 2.4 cm² versus 1.8 cm² favoring balloon valvuloplasty 4

• Similar restenosis rates between balloon valvuloplasty (3 patients) and surgery (4 patients) in randomized trials 4

• Lower cost and elimination of thoracotomy make balloon valvuloplasty preferable for all patients with favorable anatomy 4

Complications and Safety Profile

The procedure has an acceptable safety profile:

• Mortality occurs in 0-0.5% of cases 5

• Cerebrovascular accidents occur in 1-2% of patients 5

• Severe mitral regurgitation requiring surgery develops in 1.6-3% of cases, typically from torn leaflets, chordal attachments, or papillary muscle rupture 1, 5

• Residual atrial septal defects may persist in some patients after transseptal puncture 4

Absolute Contraindications

Do not perform balloon valvuloplasty in these situations:

• Presence of left atrial thrombus (must be excluded by transesophageal echocardiography) 1

• Moderate to severe mitral regurgitation at baseline 1

• Mild mitral stenosis (mitral valve area >1.5 cm²) without hemodynamically significant features 1

Predictors of Long-Term Success

Three independent factors predict sustained benefit:

• Lower Wilkins echocardiographic score (≤8) is the strongest predictor of event-free survival 2, 3

• Lower left ventricular end-diastolic pressure (≤10 mm Hg) predicts better outcomes 2

• Less severe baseline symptoms (NYHA class I-II versus III-IV) correlates with longer event-free survival 2, 3

• Post-procedural mitral valve area >1.75 cm² independently predicts favorable long-term results 3

Clinical Algorithm for Decision-Making

Follow this stepwise approach:

1. Confirm rheumatic etiology with commissural fusion pattern on echocardiography 1

2. Assess severity: mitral valve area ≤1.5 cm², mean gradient ≥5-10 mm Hg, pulmonary artery systolic pressure ≥30 mm Hg 1

3. Evaluate symptoms: NYHA class II-IV warrants intervention; asymptomatic patients require pulmonary hypertension (>50 mm Hg) 1

4. Perform transesophageal echocardiography to exclude left atrial thrombus and assess valve morphology 1

5. Calculate Wilkins score: scores ≤8 predict excellent outcomes; scores >8 suggest consideration of surgery if high-risk features present 2, 3

6. Exclude moderate-severe mitral regurgitation by Doppler echocardiography 1

7. Proceed with balloon valvuloplasty if all criteria met; refer to surgery if contraindications exist 1