Aortic Valve Calcium Score Quantification by Contrast Cardiac CT: Correlations With Echocardiography and Optimal Thresholds | Circulation: Cardiovascular Imaging
BACKGROUND: Aortic valve calcium score (AVCa) measured on noncontrast computed tomography (CT) is well-established for grading aortic stenosis (AS) severity. However, thresholds for AVCa measured on contrast CT remain uncertain. We evaluated correlations, associated factors, and severity thresholds of AVCa measured on contrast CT against transthoracic echocardiography (TTE) measures of AS. METHODS: Patients with native AS undergoing transcatheter aortic valve replacement evaluation from 2019 to 2020 who underwent TTE and contrast-enhanced CT were retrospectively studied (n=1035, age 79±9 years, 429 (41.5%) women, 906 (87.5%) severe and 129 (12.5%) moderate AS by TTE). AVCa was measured using the modified Agatston method with the minimum threshold of 4 SD above the mean ascending aorta blood pool Hounsfield units. Receiver-operating characteristics analysis and Youden index were used to define sex-specific optimal AVCa thresholds for identifying severe AS defined by TTE (aortic valve ar