Vena contracta area for severity grading in functional and degenerative mitral regurgitation: a transoesophageal 3D colour Doppler analysis in 500 patients

Aims: Vena contracta area (VCA3D), derived by 3D colour Doppler echocardiography, has already been validated against cardiac magnetic resonance imaging, but the number of clinical studies to define cut-off values for grading of mitral regurgitation (MR) is limited. Aim of the study was to assess VCA3D in a large population of patients with functional (FMR) and degenerative MR (DMR). Methods and results: Transoesophageal echocardiography was performed in 500 patients with MR. The following 2D parameters were assessed for grading of MR: vena contracta width, effective regurgitant orifice area (EROAPISA), and regurgitation volume (RVPISA). VCA3D and the corresponding regurgitation volume (RVVCA) were quantified using 3D colour Doppler loop and CW Doppler tracing of the regurgitant jet. In 104 patients a 3D dataset of the left ventricle (LV) and the left ventricular outflow tract (LVOT) was acquired. As a reference method, regurgitation volume (RV3D) was calculated as difference between LV overall and LVOT stroke volumes. For prediction of severe MR, VCA3D yielded higher values of area under the ROC curve compared to EROAPISA (overall patient group 0.98 for VCA3D vs. 0.90 for EROAPISA, P < 0.001; FMR group 0.97 for VCA3D vs. 0.92 for EROAPISA, P = 0.002). RVVCA correlated closer with RV3D compared to RVPISA (r = 0.96 for RVPISA, r = 0.79 for RVPISA). Conclusion: This study delivers cut-off values for VCA3D in patients with different types of MR. VCA3D is a robust parameter for quantification of MR, showing a good correlation with the reference method using 3D datasets of LV.