Multimo dality assessment of aortic valve area in aortic stenosis: a multicenter validation study

Abstract Objectives Transthoracic echocardiography (TTE) is the standard modality for grading aortic stenosis (AS) severity. Transesophageal echocardiography (TOE) allows direct aortic valve area (AVA) planimetry (AVA TOE ), while computed tomography angiography (CTA) offers a non-invasive alternative (AVA CTA ). This study aimed to evaluate the correlation between AVA measurements across modalities and to determine a diagnostic AVA CTA threshold for severe AS. Methods This retrospective study included a single-center derivation cohort of 176 patients (mean age 80.0 ± 7.7 years, 52.8% male) with moderate to severe AS who underwent full-cycle CTA, TTE, and TOE. AVA CTA was measured by two independent raters. Correlation with AVA TOE and other parameters was assessed. Receiver operating characteristic (ROC) analysis was used to define an optimal AVA CTA threshold for severe AS, which was validated in a multi-center cohort of 407 patients (mean age 80.9 ± 6.7 years, 52.8% male) with comparable characteristics. Results Mean AVA CTA was 0.96 ± 0.28 cm² with a high interrater reliability (IRR = 0.84), compared to a mean AVA TOE of 0.88 ± 0.26 cm² (Pearson’s r = 0.73). ROC analysis identified 0.96 cm² as the optimal AVA CTA threshold for diagnosing severe AS (AUC = 0.846; sensitivity = 71.7%; specificity = 89.8%) compared to TOE grading. This threshold yielded good diagnostic performance in the validation cohort (AUC = 0.817; sensitivity = 78.2%; specificity = 72.6%). Conclusions AVA CTA demonstrated high reliability, showing a strong correlation with AVA TOE . The 0.96 cm² threshold, defined in the derivation cohort, performed well in the validation cohort for assessing aortic stenosis severity.