Three-Dimensional Echocardiography Compared With Computed Tomography to Determine Mitral Annulus Size Before Transcatheter Mitral Valve Implantation

Abstract

Background— Previously, through the use of computed tomography (CT), it has been proposed that D-shaped versus saddle-shaped mitral annulus (MA) segmentation is more biomechanically appropriate to determine transcatheter mitral valve implantation size and eligibility. Methods and Results— Forty-one patients with severe mitral regurgitation being considered for transcatheter mitral valve implantation who had undergone cardiac CT and 3-dimensional transesophageal echocardiography (3D-TEE) were retrospectively evaluated. A standardized segmentation protocol for the D-shaped MA was developed using Philips Q-Laboratory mitral valve quantification software. MA dimensions were compared using Spearman’s rank correlation and Bland–Altman analysis. Inter- and intraobserver agreement was quantified by intraclass correlation coefficient and Bland–Altman analysis. Mean age was 77±14 years; 71% male (n=29); mitral regurgitation pathogenesis was functional in 54% (n=22) and myxomatous in 46% (n=19). Mean MA area and circumference by 3D-TEE and CT were 11.3±2.7 versus 11.4±3.0 ( P =0.67) and 124.1±15.6 versus 123.9±15.5 ( P =0.79), respectively, with excellent correlation between modalities ( r =0.84 and r =0.86; P <0.0001) and no systematic bias (−0.20±1.8 cm 2 [−3.7 cm 2 ; 3.3 cm 2 ], 0.37±9 mm [−18.0 mm; 17.27 mm]). Mean septal-to-lateral and inter-trigone distances by 3D-TEE and CT were 33.2±4.7 versus 32.5±4.4 ( P =0.24) and 31.7±3.5 versus 32.6±3.6 ( P =0.06), respectively, with good correlation ( r =0.69 and r =0.71; P <0.0001) and no systematic bias (0.77±3.8 mm [−6.7 mm; 8.2 mm], −1.5±3.1 mm [−4.6 mm; 7.6 mm]). There was excellent intra- and interobserver agreement according to intraclass correlation coefficients >0.90 for all parameters. Conclusions— Similar to cardiac CT, 3D-TEE allows for D-shaped MA segmentation with no systematic difference in MA dimensions between modalities. This study supports the utilization of 3D-TEE as a complementary tool to CT assessment of the D-shaped MA to determine transcatheter mitral valve implantation size.