Intraoperative comparison of 2D versus 3D transesophageal echocardiography for quantitative assessment of mitral regurgitation

Background: Effective regurgitant orifice area (EROA) can be represented by 3D echocardiographic vena contracta cross-sectional area (3D-VCA) as a reference method for the quantification of mitral regurgitation (MR) without making any geometrical assumptions. EROA can also be derived from 3D PISA technique with a hemispherical (HS) or hemielliptical (HE) assumption of the proximal flow convergence. However, it is not clear whether HS-PISA and HE-PISA has better agreement with 3D-VCA. Aims: This study was conducted to compare the EROA and Rvol obtained from 3D-VCA with those obtained from 2D-VC, 2D-HS-PISA, 3D-HS-PISA, and 3D-HE-PISA. Setting: Tertiary care hospital. Design: Prospective observational study. Materials and Methods: After anesthesia induction, 43 consecutive patients were evaluated with RT-3D-TEE after acquiring images from midesophegeal views and performing the offline analysis of volume dataset. 3D-VCA was measured using multiplanar reconstruction mode and EROA and regurgitant volume were estimated using HS-PISA and HE-PISA methods. The HE-PISA was calculated by using the Knud Thomsen formula. Statistical Analysis: Agreement between methods to estimate EROA and regurgitant volumes were tested using Bland-Altman analysis. The interobserver variability and intraobserver variability were assessed using an intraclass correlation coefficient. Results: The EROA estimated by 3D-VCA was larger than EROA obtained by 2D-HS-PISA and 3D-HS-PISA, which were significantly greater than 3D-HE-PISA. 3D-HS-PISA-EROA showed the best agreement with 3D-VCA (bias: 0.21; limits of agreement: -0.01 to 0.41; SD: 0.1). Correlation between various methods as compared to 3D-VCA was better in the organic MR group than functional MR group. Conclusion: 3D-HS-PISA showed the best agreement with 3D-VCA compared to other PISA methods. Better correlation between PISA-EROA and 3D-VCA was observed in patients with organic MR than functional MR.