Aortic Valve Calcium Score Quantification by Contrast Cardiac CT: Correlations With Echocardiography and Optimal Thresholds

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: ) in the derivation cohort and assessed when applied to the validation cohort. RESULTS: , and 673±485 mg, respectively. Multivariable linear regression identified women to be associated with lower AVCa (β-coefficient, -358), while chronic kidney disease was associated with a higher AVCa (β-coefficient, 171). Optimal severe AS thresholds of ≥1840 modified AU for men and ≥1430 modified AU for women were determined, with area under curve (95% CIs) and sensitivities/specificities of 0.809 (0.749-0.869, 71.3%, 82.2%) for men and 0.822 (0.751-0.892), 73.4%/78.9% for women in the derivation cohort, and 0.830 (0.786-0.875), 75.9%/87.5% for men and 0.780 (0.670-0.890), 77.5%/71.4% for women in the validation cohort. CONCLUSIONS: AVCa by contrast CT is a useful tool for identifying severe AS by TTE, with sex-specific thresholds for severe AS identified. Further studies are necessary to externally validate our findings and evaluate their prognostic significance.