# Multimodality assessment of aortic valve area in aortic stenosis: a multicenter validation study

## TL;DR

This study compares different methods for measuring aortic valve area in aortic stenosis and finds a reliable threshold for diagnosing severe cases.

## Contribution

The study introduces a validated AVACTA threshold of 0.96 cm² for diagnosing severe aortic stenosis.

## Key findings

- AVACTA measurements showed high interrater reliability (IRR = 0.84) and strong correlation with AVATOE (Pearson’s r = 0.73).
- The AVACTA threshold of 0.96 cm² achieved 71.7% sensitivity and 89.8% specificity in the derivation cohort.
- The threshold performed well in a multi-center validation cohort with an AUC of 0.817.

## Abstract

Transthoracic echocardiography (TTE) is the standard modality for grading aortic stenosis (AS) severity. Transesophageal echocardiography (TOE) allows direct aortic valve area (AVA) planimetry (AVATOE), while computed tomography angiography (CTA) offers a non-invasive alternative (AVACTA). This study aimed to evaluate the correlation between AVA measurements across modalities and to determine a diagnostic AVACTA threshold for severe AS.

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. AVACTA was measured by two independent raters. Correlation with AVATOE and other parameters was assessed. Receiver operating characteristic (ROC) analysis was used to define an optimal AVACTA 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.

Mean AVACTA was 0.96 ± 0.28 cm² with a high interrater reliability (IRR = 0.84), compared to a mean AVATOE of 0.88 ± 0.26 cm² (Pearson’s r = 0.73). ROC analysis identified 0.96 cm² as the optimal AVACTA 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%).

AVACTA demonstrated high reliability, showing a strong correlation with AVATOE. The 0.96 cm² threshold, defined in the derivation cohort, performed well in the validation cohort for assessing aortic stenosis severity.

The online version contains supplementary material available at 10.1007/s10554-025-03576-7.