Intraoperative Transesophageal Echocardiography Quantification of Mitral Regurgitation by Regurgitation Volume and Fraction Using 2D and 3D Techniques

Background and Aims: Intraoperative quantification of mitral regurgitation (MR) is sometimes necessary to quantify the severity of incidentally detected MR during cardiac surgeries. We aimed to compare and correlate the regurgitant volume (Rvol) and regurgitant fraction (RF) using 2D proximal isovelocity surface area (PISA) and 3D vena contracta area (VCA) with the 3D volumetric method and the integrated multiparametric approach. Methods and Materials: A prospective observational study was conducted on 37 patients undergoing mitral valve surgery for MR. Intraoperative quantification of the severity of MR was done using 2D PISA and 3D VCA methods and was compared with the 3D volumetric method. All three methods were compared with the integrated multiparametric method to obtain cutoff values for identifying severe MR. Results: The correlation coefficients for Rvol with VCA and PISA with the 3D volumetric method were 0.688 and 0.58, respectively. VCA and PISA overestimated the Rvol (VCA = 77.93 ± 27.82 ml, PISA = 76.13 ± 19.25 ml) compared to the 3D volumetric method (66.12 ± 20.30 ml); the RF by the three methods was comparable. Using the receiver operating characteristic–area under curve (AUC) comparing Rvol by these methods with the integrated multiparametric method, the 3D volumetric method performed the best. Conclusion: The Rvol VCA and PISA overestimated MR severity compared to the 3D volumetric method with moderate to good correlation. Rvol 3D was superior with a higher AUC when compared with the integrated multiparametric approach. The RF by the three methods was comparable, albeit with a higher threshold in quantifying severity compared to the conventional criteria.