A New Three-Dimensional Echocardiography Method to Quantify Aortic Valve Calcification.

ABSTRACT

BACKGROUND: Aortic valve calcification (AVC) quantification is computed from multidetector computed tomography (MDCT). The aim of this study was to test the hypothesis that three-dimensional (3D) transthoracic echocardiography can be used to provide a bedside method to assess AVC. METHODS: The study included 94 patients (mean age, 78 ± 12 years; mean aortic valve [AV] area, 1.0 ± 0.6 cm2) referred for MDCT and echocardiography for AV assessment. Apical 3D full-volume data sets focused on the AV region were acquired during transthoracic echocardiography, and a region-growing algorithm was applied offline to compute 3D transthoracic echocardiographic AVC (AVC-3DEcho). AVC-3DEcho was compared with AVC by MDCT and with calcium weight in the subgroup of patients referred for surgery, with explanted AVs analyzed by a pathologist (n = 22). RESULTS: In the explanted valve group, AVC-3DEcho score exhibited fair correlations with MDCT score (r = 0.85, P < .001), calcium load (r = 0.81, P < .001), and peak AV velocity (r = 0.64, P < .001). In the overall population, AVC-3DEcho score correlated modestly with MDCT score (r = 0.61, P < .001) but had similar accuracy to identify severe aortic stenosis (area under the curve = 0.94). AVC-3DEcho > 1,054 mm3 identified severe aortic stenosis with specificity of 100% and sensitivity of 76%. In addition, AVC-3DEcho was associated with the presence of significant paravalvular regurgitation after transcatheter aortic valve implantation. Finally, intraobserver and interobserver variability for AVC-3DEcho score was 4.2% and 8.9%, respectively. CONCLUSIONS: AVC-3DEcho correlated with calcium weight obtained from pathologic analysis and MDCT. These data suggest that a bedside method for quantifying AV calcification with ultrasound is feasible.