Yeo's Index for Mitral Valve Assessment during Percutaneous Transvenous Mitral Commissurotomy

Rheumatic mitral stenosis (MS) severity assessment by planimetry, pressure half-time (PHT), and continuity equation (CE) has limitations. Yeo's index, the product of mitral leaflet separation index and dimensionless index, combining anatomic and hemodynamic severity, offers a promising alternative.

The objective of this study was to evaluate the Yeo's index accuracy in MS before and after percutaneous transvenous mitral commissurotomy (PTMC) and its correlation with conventional methods and mitral valve area (MVA) by three-dimensional (3D) transesophageal echocardiography (TEE).

A prospective, single-center interventional study of 100 patients with severe symptomatic MS undergoing PTMC. Transthoracic echocardiography and 3D TEE were performed pre-PTMC and 48 h post-PTMC.

The mean age was 35.94 years, with 68% of females and 34% in atrial fibrillation (AF). The mean Yeo's index before PTMC was 0.16 ± 0.08 cm, and after PTMC, it increased to 0.31 ± 0.12 cm. Pre-PTMC, the Yeo's index showed moderate-to-strong positive correlations with MVA by PHT (r = 0.584), planimetry (r = 0.483), 3D TEE (r = 0.592), and CE (r = 0.665); P < 0.0001. Post-PTMC, correlations remained strong with CE (r = 0.665) and 3D TEE (r = 0.643); P < 0.0001. Receiver operating curve analysis confirmed its strong predictive value, with a pre-PTMC cutoff of < 0.147 cm identifying very severe MS (area under the curve [AUC]: 0.974; sensitivity: 94.74% and specificity: 100%) in non-AF and AF patients (AUC = 0.95; sensitivity: 90% and specificity: 100%). Severe MS was defined with a cutoff of 0.147 - 0.26 cm (AUC = 0.964 in non-AF and 0.95 in AF).

The Yeo's index is a reliable, noninvasive tool for assessing MS severity both pre-and post-PTMC, demonstrating strong correlations and accuracy even in AF.