What is the clinical evidence from this study?

Study design: Observational. Population: Aortic valve stenosis (n=168). Intervention: Computed tomography (CT) vs. Transthoracic echocardiography (TTE). Primary outcome: Effective valve area (EOA) (p=<0.001).

What question did this study set out to answer?

This research aims to validate the effectiveness of computed tomography in assessing the severity of aortic valve stenosis compared to traditional echocardiography.

February 28, 2026

Computed tomography can assess aortic valve stenosis by planimetry, enhances the continuity equation, reveals an anatomical ratio that mimics the dimensionless velocity index and demonstrates limitations in the use of calcification in stenosis severity assessment

Q: What are the key findings of this study?

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).

Q: What question did this study set out to answer?

This research aims to validate the effectiveness of computed tomography in assessing the severity of aortic valve stenosis compared to traditional echocardiography.

Key Result

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).

Key Points

This research aims to validate the effectiveness of computed tomography in assessing the severity of aortic valve stenosis compared to traditional echocardiography.
Included 168 symptomatic patients with probable severe aortic stenosis.
Compared computed tomography (CT) and transthoracic echocardiography (TTE) measurements of aortic valve area.
Evaluated correlations between effective valve area, anatomical valve area, and aortic valve calcification.
CT effective valve area (CT-EOA) and anatomical valve area (CTP-AVA) were similar, mean 1.13 cm2, R2 0.359, P<0.001.
TTE effective valve area (TTE-EOA) was significantly smaller, mean 0.82 cm2, P<0.001 compared to CT.
Dimensionless velocity index closely matched the anatomical valve index with R2 = 0.378, P<0.001, establishing the relevance of CT measures.

Study Design

Type

Observational (n=168)

Structured PICO

Does computed tomography (CT) provide accurate assessment of aortic valve stenosis severity compared to transthoracic echocardiography (TTE) in patients with symptomatic probable severe AS?

Population

157 analyzed patients (from 168 sequential patients) with symptomatic probable severe aortic stenosis (119 tricuspid, 38 bicuspid).

Intervention

Computed tomography (CT) assessment of aortic valve stenosis (CT planimetry for anatomical valve area, CT-derived LVOT for continuity equation, and CT aortic valve calcification).

Comparator

Transthoracic echocardiography (TTE) assessment of aortic valve stenosis.

Outcome

Aortic valve area (AVA) assessed by continuity equation (effective valve area) and CT planimetry (anatomical valve area).surrogate

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.

Main Result

Absolute Event Rate: 1.13% vs 0.82%

p-value: p=<0.001

Abstract

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.

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