Mitral Leaflet Separation Index: A New Method for the Evaluation of the Severity of Mitral Stenosis? Usefulness Before and After Percutaneous Mitral Commissurotomy

Yeo's index: A novel index that combines anatomic and haemodynamic assessment of the severity of mitral stenosis

BACKGROUND

A mitral leaflet separation index (MLSI), measuring the anatomical separation of the mitral valve (MV) leaflet tips in diastole, was previously described as an accurate method of assessing mitral stenosis (MS). We propose a novel modification of the MLSI by including a hemodynamic assessment which we term Yeo's index that may improve its diagnostic performance.

METHODS AND RESULTS

We retrospectively studied 174 patients with varying severity of MS without significant mitral regurgitation, aortic valve disease or ventricular septal defect. MLSI was measured in 2 orthogonal views on transthoracic echocardiography as previously described. MV dimensionless index (DI) was calculated by dividing the left ventricular outflow tract pulsed-wave Doppler time velocity integral (TVI) by the MV continuous-wave Doppler TVI. We defined Yeo's index as the product of MLSI and DI. With linear correlation, Yeo's index demonstrated good correlation against MVA by planimetry (r = 0.728), pressure half-time (r = 0.677), and continuity equation (r = 0.829), with improved performance over the MLSI. Using ROC analysis, Yeo's index demonstrated good ability to correctly classify MS as severe (MVA ≤1.5cm2) (AUC 0.874, 95% CI 0.816-0.920). Yeo's index ≤0.260 cm correctly classified severe MS with sensitivity of 82% and specificity of 80%. Presence of AF did not affect the performance of Yeo's index. Yeo's index ≤0.147 cm also identified very severe MS (MVA ≤ 1.0 cm2) with specificity of 94% and sensitivity of 78%.

CONCLUSION

Yeo's index performed well in identifying severe MS and may be a useful adjunct to existing measures of MS severity.

Mitral leaflet separation index for mitral valve assessment during balloon mitral valvuloplasty

OBJECTIVE

The objective of the study was to evaluate the accuracy of the mitral leaflet separation index (MLSI) in selected patients with mitral stenosis, before and after percutaneous balloon mitral valvuloplasty (PBMV), compared to conventional methods with transthoracic echocardiography [TTE].

METHODS

A prospective study was conducted in 30 patients, ages 20-60 years, with severe symptomatic mitral stenosis (MS) who had PBMV in the Cardiology Department, Zagazig University and National Heart Institute. A mean of three to five measurements of MLSI was taken in diastole in the parasternal long-axis and apical four-chamber views. The MLSI was re-measured 24-48 hours after PBMV. We calculated the correlation of the MLSI, pre and post BMV, with two-dimensional (2D) MV planimetry and pressure half-time (PHT) methods to assess MVA.

RESULTS

There was a positive, highly significant correlation between pre PBMV 2D planimetry and MLSI (r = .665, P-value < .001) as well as post PBMV 2D planimetry and MLSI (r = .410, P-value = .025). A positive highly significant correlation was also noted between pre PBMV PHT and MLSI (r = .678, P-value <.001) and between post PBMV PHT and MLSI (r = .706, P-value <.001).

CONCLUSION

Mitral leaflet separation index is an easy and reliable measurement for the assessment of mitral stenosis before and after PBMV.

Mitral leaflet separation index. An easy two dimensional echocardiography technique for assessment of mitral valve area before and after percutaneous balloon mitral valvuloplasty

AIM

To evaluate the reliability of the mitral leaflet separation (MLS) index against the traditional echocardiographic methods in measuring mitral valve area (MVA) pre and post percutaneous balloon mitral valvuloplasty (PBMV).

METHODS

Ninety patients suffering symptomatic moderate to severe MS underwent PBMV at Ain Shams University Hospital in cardiology department. Seventy of the patients were females representing 77.8% and 20 were males representing 22.2%. Their age ranged from 22 to 56 years. All patients were subjected to full transthoracic echocardiography (TTE) examination pre and post PBMV. MLS index was introduced as a comparative parameter with traditional echocardiographic methods for assessment of MVA, measuring average of distance between tips of MV leaflets in parasternal long axis and four chamber two dimensional echocardiographic views.

RESULTS

MVA increased from 0.95 ± 0.28 to 2.21 ± 0.41 cm2 (P=0.001) using 2D planimetry; and increased from 0.93 ± 0.23 to 2.21 ± 0.46 cm2 (P= 0.0011) by pressure half time method (PHT). MLS index was correlated with MVA by 2D planimetry pre and post PBMV (r=0.453) and (r=0.668) respectively (p=0.0001) and strongly correlated with MVA using PHT post PBMV (r=0.768) (p=0.0001). Post PBMV 14 patients suffered significant mitral regurgitation 3 of them were transferred to surgery. MLS index above 11.75 mm and below 9.15 mm had excellent positive predictive value for detecting mild and severe MS respectively.

CONCLUSION

The MLS index it is a simple and effective method for assessment of the MVA, it has an excellent correlation with MVA with an excellent sensitivity and specificity for the prediction of effective MVA. The MLS index cannot evaluate outcome of PBMV because it is an anatomical parameter and not flow dependent thus does not correlate with grades of mitral regurgitation.

Mitral leaflet separation to evaluate the severity of mitral stenosis: Validation of the index by transesophageal three-dimensional echocardiography

BACKGROUND

Determining severity of mitral stenosis (MS) by planimetry of mitral valve orifice area (MVA) has been a challenging issue in clinical practice, especially for less experienced cardiologists. Mitral leaflet separation (MLS) has shown a good correlation with MVA measurements. However, it has never been validated against multiplane 3DTEE planimetry (MVA_3D ). We aimed to evaluate the accuracy of MLS index (MLSI_2D ) in predicting MS severity.

METHODS

We prospectively enrolled 144 patients with MS who underwent clinically indicated 2DTTE and 3DTEE. MLSI_2D was yield by averaging the maximal leaflet tip distance in diastole, in parasternal long-axis and apical four-chamber views. MVA_3D was used as the reference method.

RESULTS

MLSI_2D showed an excellent discriminatory ability between different grades of MS (P < .001). There was a significant positive correlation between MLSI_2D and MVA_3D (r = .93, P < .001) irrespective of concurrent mitral regurgitation (r = .94, P < .001) and/or atrial fibrillation (r = .92, P < .001). By receiver operating characteristic (ROC) curves, MLSI_2D  ≤ 8.6 mm showed 100% sensitivity and 76% specificity for very severe MS. MLSI_2D  ≥ 11.2 mm determined progressive MS with 100% sensitivity and 82% specificity. The study population was then divided into a derivation group and a validation group. A regression equation for MVA by MLSI_2D was derived in first group. Then, the MVA was calculated by this equation in validation group and was not significantly different from MVA_3D .

CONCLUSION

MLSI_2D showed an excellent ability to assess MS severity and correlates well with planimetered MVA measured by 3DTEE.