Computed tomography planimetry accurately assessed aortic stenosis severity, yielding a mean effective orifice area of 1.13 cm2 compared to 0.82 cm2 by transthoracic echocardiography (P<0.001).
Observational (n=168)
Does computed tomography (CT) provide accurate assessment of aortic valve stenosis severity compared to transthoracic echocardiography (TTE) in patients with symptomatic probable severe AS?
CT planimetry and CT-derived LVOT measurements provide a reliable assessment of aortic stenosis severity, highlighting the variability and potential underestimation of valve area by TTE.
Absolute Event Rate: 1.13% vs 0.82%
p-value: p=<0.001
AIM Transthoracic echocardiography (TTE) grades aortic valve stenosis (AS) severity. However, this is often discordant when velocity and aortic valve area (AVA) grade boundaries are considered. We evaluated computed tomography (CT) and TTE datasets to validate CT measures of AS. MATERIALS AND METHODS A total of 168 sequential patients with symptomatic probable severe AS were included. CT and TTE measures of AS were made. The AVA was assessed by (1) the continuity equation, which measures the effective valve area (EOA) and (2) CT planimetry, which measures the anatomical valve area (CTP-AVA). The EOA as measured by TTE (TTE-EOA) or CT (CT-EOA) varied by whether the TTE or CT-derived left ventricular outlet area (LVOT) was used in the calculation with the TTE Doppler. Area relationships and CT aortic valve calcification (CT-AVC) data were also assessed. RESULTS After exclusions, 157 datasets were analysed. 119 (75.8%) had tricuspid (TAV) and 38 (24.2%) had bicuspid (BAV) aortic valve. Mean CT-EOA (1.13 ± 0.42 cm2) and CTP-AVA (1.13 ± 0.37 cm2) were near identical and correlated (R2 0.359, P<0.001). The TTE-EOA (0.82 ± 0.31 cm2) was smaller as the TTE-LVOT area (3.66 ± 0.87 cm2) was smaller than CT (5.04 ± 1.23 cm2), P<0.001. Dimensionless velocity index (0.22 ± 0.07) matched an anatomical valve index (AVI) (planimetered valve area/LVOT area) (0.23 ± 0.08), R2 = 0.378, P<0.001. CT-AVC was unhelpful in confirming severe AS with weak correlations. CONCLUSION We confirm the utility of CTP-AVA to assess aortic stenosis severity, quantify and highlight the variability of TTE-EOA, describe an AVI (explaining the DVI), and show that CT-AVC is inaccurate in assessing AS severity in individuals.
Hamilton et al. (2026) conducted an observational in Aortic valve stenosis (n=168). Computed tomography (CT) vs. Transthoracic echocardiography (TTE) was evaluated on Effective valve area (EOA) (p=<0.001). Computed tomography planimetry accurately assessed aortic stenosis severity, yielding a mean effective orifice area of 1.13 cm2 compared to 0.82 cm2 by transthoracic echocardiography (P<0.001).