Hemodynamic significance of mitral stenosis: use of a simple, novel index by 2-dimensional echocardiography.

Objective: We sought to assess the hemodynamic significance of mitral stenosis (MS) using a new index.

Methods: We studied 88 patients with MS. Maximum separation of mitral leaflet tips in diastole in parasternal long-axis and apical 4-chamber views was measured. These two parameters were averaged to yield the mitral leaflet separation index. The index was compared with mitral valve area by planimetry and pressure half-time.

Results: The mitral leaflet separation index was measurable in 76 (86.4%) patients. There was excellent correlation with mitral valve area by planimetry (r = 0.91, P < .001) and pressure half-time (r = 0.86, P < .001) across a wide range of mitral valve areas. Good correlation was found even in atrial fibrillation (r = 0.86 and r = 0.79, respectively). The index could discriminate between hemodynamically significant and insignificant MS (P < .001). An index of 0.81 cm or less predicted severe MS with 92.3% sensitivity and 100% specificity whereas a value of 1.11 cm or more identified mild MS with 85.7% sensitivity and 100% specificity.

Conclusion: The mitral leaflet separation index is an independent and reliable measure of MS severity that is easy to measure.