Quantitative analysis of mitral valve geometry by transthoracic three-dimensional echocardiography: reference values, feasibility and reproducibility

Background: Quantitative analysis of mitral valve (MV) can discriminate among various mechanisms causing valve insufficiency. There are no established reference values for MV geometry, nor data on its feasibility and reproducibility with latest transthoracic 3D echocardiography (3DTTE). Methods: Eighty-one consecutive healthy volunteers (43+13 years, range 18-70; 33 men) with good apical window underwent a 3D full-volume acquisition of MV apparatus (32+2 vps) using Vivid E9 (BT 12, GE Healthcare, Horten, N). MV datasets were analyzed offline using a software recently developed for 3DTTE (TomTec MV assessment 2.0, Unterschleissheim, D). Intra- and inter-observer reproducibility were assessed in 15 subjects and expressed as intraclass correlation coefficients (ICC). Results: Five subjects were excluded due to low quality of 3D dataset with poor MV tracking (feasibility 94%). The average analysis time of one dataset (including manual editing) was 2’. Reference values of MV parameters and their reproducibility are reported in Table. Leaflet tenting and annulus measures were positively correlated with body surface area (BSA, r=0.34-0.53, p , 0.001), but not with age. After correcting for BSA, there were no gender differences in MV parameters. Conclusion: Quantitative analysis of MV by 3DTTE is highly feasible and reproducible, and reference values are reported. Our findings may support the implementation of MV quantitative analysis by 3DTTE in clinical settings.