Accuracy of aortic valve calcification volume score for identification of significant aortic stenosis on non-electrocardiographic-gated computed tomography compared to the Agatston scoring system

Considering the absence of reports validating the precision of the volume score and the relationship between the volume and Agatston scores, this study evaluated the accuracy of the volume score compared to the Agatston score for the quantitative measurement of aortic valve calcification (AVC) on non-electrocardiographic-gated computed tomography (CT). We retrospectively analysed the AVC scores of 5385 patients who underwent transthoracic echocardiography between March 1, 2013 and December 26, 2019 ​at our institution, using non-contrast non-electrocardiographic-gated CT. The thresholds for significant aortic stenosis (AS) were computed using receiver operating characteristic curves based on the AVC scores. The area under the curve (AUC) of the Agatston and volume scores for significant AS were compared to evaluate the accuracy of the scoring method. All sex-specific AVC thresholds of the volume score for significant AS (moderate and high AS severity, moderate and high AS severity without discordance, discordant severe AS, and concordant severe AS) showed high sensitivity and specificity (AUC, 0.978–0.996; sensitivity, 94.2–98.4%; specificity, 90.1–100%). No significant differences in the AUC were observed between the Agatston and volume scores for significant AS in male and female patients. All volume score threshold values showed high sensitivity and specificity for identifying significant AS. The accuracy of the test for AVC thresholds of the volume score for significant AS was comparable to that of the Agatston score. Our findings raise questions about the significance of weighting calcium density in the Agatston score for assessing AS severity.