Wilkins Score for Mitral Valve Assessment
The Wilkins score is an echocardiographic scoring system (range 0-16) that evaluates mitral valve morphology across four parameters—leaflet mobility, thickening, calcification, and subvalvular disease—with scores ≤8 predicting favorable outcomes for percutaneous balloon mitral commissurotomy (PBMC), though patients with scores >8 may still benefit if they are poor surgical candidates. 1
Components of the Wilkins Score
The Wilkins score assesses four distinct anatomical features, each graded 1-4 points 2:
- Leaflet mobility: Evaluates the degree of restriction in leaflet motion
- Leaflet thickening: Measures the extent of valve thickening
- Leaflet calcification: Assesses calcium deposition within the valve
- Subvalvular disease: Evaluates thickening and fusion of the chordal apparatus
Of these four components, valvular thickening correlates most strongly with procedural outcomes (r = -0.47, p <0.0001). 2
Clinical Application and Predictive Value
Optimal Candidates (Score ≤8)
Patients with Wilkins scores ≤8 demonstrate 84% likelihood of achieving optimal outcomes, defined as final mitral valve area ≥1.5 cm² with ≥25% increase from baseline. 2 The 2014 AHA/ACC guidelines support PBMC as the preferred intervention for symptomatic patients with favorable valve morphology (score ≤8). 1
The 2017 ESC/EACTS guidelines similarly recommend PBMC as Class I indication for symptomatic patients without unfavorable characteristics. 1
Suboptimal Anatomy (Score >8)
Despite traditional teaching, 42% of patients with Wilkins scores >8 still achieve optimal outcomes (≥25% increase in mitral valve area to >1.5 cm²), and 38% demonstrate event-free survival at 1.8 years. 1 This finding has important clinical implications:
For severely symptomatic patients (NYHA class III-IV) with severe MS (mitral valve area ≤1.5 cm²) who are poor surgical candidates, PBMC may be considered even with suboptimal valve anatomy (Class IIb recommendation). 1
Recent data from 2023 challenges the rigid cutoff of 8, showing no significant difference in procedural success, complications, or mitral regurgitation rates between patients with scores ≤8 versus >8. 3
A 2013 study of patients with Wilkins scores 9-11 demonstrated similar success rates (89.9% vs 95.8%, p=0.69) and need for reintervention (22% vs 27.3%, p=0.594) compared to those with scores ≤8. 4
Important Caveats and Limitations
Predictive Limitations
The Wilkins score has a sensitivity of only 72% and specificity of 73% for predicting good outcomes, with substantial scatter in the data (r = -0.40, p <0.0001). 2 This moderate predictive ability means the score should not be used in isolation.
Additional Prognostic Factors
Commissural calcification independently predicts procedural success and should be assessed alongside the Wilkins score. 1 The 2017 integrated approach combining Wilkins score with commissural calcium score and commissural area ratio provides superior outcome prediction. 5
Long-term outcomes are determined by multiple factors beyond valve morphology, including: 6
- Post-procedural mitral valve area (≤1.75 cm² predicts worse outcomes, HR 1.67)
- Pre-procedural NYHA functional class (III-IV predicts worse outcomes, HR 1.62)
- Patient age (HR 0.97 per year)
- Left atrial size (smaller size predicts success, OR 0.96)
Clinical Decision Algorithm
For symptomatic patients with severe MS (mitral valve area ≤1.5 cm²): 1
- Calculate Wilkins score and assess for commissural calcification
- If score ≤8 without moderate-to-severe MR or left atrial thrombus: PBMC is Class I indication
- If score >8 but patient is high surgical risk or refuses surgery: Consider PBMC (Class IIb) after discussing potential complications
- If score >8 and patient is acceptable surgical candidate: Mitral valve surgery is preferred
For asymptomatic patients: 1
- Very severe MS (mitral valve area ≤1.0 cm²) with favorable morphology: PBMC is reasonable (Class IIa)
- New-onset atrial fibrillation with favorable morphology: PBMC may be considered (Class IIb)
Common Pitfalls
Do not automatically exclude patients with Wilkins scores >8 from PBMC consideration, particularly if they have: 1, 4, 3
- Prohibitive surgical risk
- Severe symptoms (NYHA III-IV)
- Absence of heavy commissural calcification
- Access to experienced operators
Remember that the Wilkins score was developed in 1990 and may not fully capture modern understanding of valve mechanics—consider integrating additional parameters like commissural morphology for more accurate risk stratification. 2, 5