Abstract 15856: Relationship Between Aortic Valve Area Assessment From Transthoracic Echocardiogram and Cardiac Computed Tomographic Angiogram

Abstract

Introduction: AVA can be estimated by either TTE or CTA however there is only limited literature assessing the concordance between these two modalities. AVA of 1.2 has been proposed as an indicator for severe AS by cardiac CTA in previous literature. Hypothesis: In our single center experience, we are hypothesizing that if use CTA AVA cut off of 1.2 cm^2, it will have high sensitivity in identifying all severe AS patients rather than using 1 cm^2 in CTA. Methods: We retrospectively studied 255 patients with severe AS who underwent both CTA and TTE at our institute from 11/2018 to 08/2021. Aortic valve area was obtained by CTA planimetry and categorized the subjects into three groups (AVA < 1 cm^2; AVA 1-1.2 cm^2; AVA > 1.2cm^2). Aortic valve area from TTE was calculated by continuity equation. The subjects were further categorized into patients with high gradient severe AS (mean gradient >40 mmhg) and low gradient severe AS. Results: Among 116 patients with low gradient severe AS (TTE AVA <1cm^2), 45 patients had CTA AVA <1 cm^2 and 39 patients had CTA AVA 1-1.2 cm^2 and 32 patients had CTA AVA >1.2 cm^2. And among 129 patients with high gradient severe AS (TTE AVA <1cm^22), 55 patients had CTA AVA <1 cm^2, 42 patients had CTA AVA 1-1.2 cm^2 and 32 patients had CTA AVA >1.2 cm^2. Overall when we use CTA AVA <1.2 cm^2 in low gradient severe AS cohort, we were able to identify 72% of severe AS patients and in high gradient severe AS cohort, we were able to identify 75.2% of severe AS patients. Conclusions: From our single center retrospective study, we are observing that for both high gradient and low gradient AS, there is high level of correlation between CTA and TTE when the AVA is either less than 1 cm^2 or when it is between 1-1.2 cm^2. However, for the AVA greater than 1.2 cm^2 there is lesser degree of correlation between the modalities especially in low gradient cohort. Overall, we suggest that using the cut off AVA 1.2 cm^2 by Cardiac CTA would achieve higher sensitivity for identifying the severe AS patients.