Dimensionless index of the mitral valve for evaluation of degenerative mitral stenosis

Purpose Degenerative mitral stenosis (DMS) is an increasingly recognized cause of mitral stenosis. The goal of this study was to compare echocardiographic differences between DMS and rheumatic mitral stenosis (RMS), identify echocardiographic variables reflective of DMS severity, and propose a dimensionless mitral stenosis index (DMSI) for assessment of DMS severity. Methods This is a single‐center, retrospective cohort study. We included patients with at least mild MS and a mean transmitral pressure gradient (TMPG) ≥4 mm Hg. Mitral valve area by the continuity equation (MVACEQ) was used as an independent reference. The DMSI was calculated as follows: DMSI = VTILVOT/ VTIMV. All‐cause mortality data were collected retrospectively. Results A total of 64 patients with DMS and 24 patients with RMS were identified. MVACEQ was larger in patients with DMS (1.43 ± 0.4 cm2) than RMS (0.9 ± 0.3 cm2) by ~0.5 cm2 (P =