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

Area of Science:

• Cardiovascular Imaging
• Radiology
• Cardiac Surgery

Background:

• Transthoracic echocardiography (TTE) is standard for aortic stenosis (AS) severity grading.
• Transesophageal echocardiography (TOE) provides direct aortic valve area (AVA) planimetry (AVA_TOE).
• Computed tomography angiography (CTA) offers a non-invasive method for AVA assessment (AVA_CTA).

Purpose of the Study:

• Evaluate the correlation between AVA measurements from CTA and TOE.
• Determine a diagnostic AVA_CTA threshold for identifying severe AS.
• Validate the CTA-derived threshold in an independent cohort.

Main Methods:

• Retrospective analysis of 176 patients with moderate to severe AS undergoing CTA, TTE, and TOE.
• Two independent raters measured AVA_CTA.
• Receiver operating characteristic (ROC) analysis to define AVA_CTA threshold for severe AS.
• Validation in a multi-center cohort of 407 patients.

Main Results:

• High interrater reliability for AVA_CTA (IRR = 0.84).
• Strong correlation between AVA_CTA and AVA_TOE (Pearson's r = 0.73).
• Optimal AVA_CTA threshold of 0.96 cm² for severe AS diagnosis (AUC = 0.846).
• Good diagnostic performance in the validation cohort (AUC = 0.817).

Conclusions:

• AVA_CTA is a reliable method for assessing AS severity.
• AVA_CTA strongly correlates with AVA_TOE.
• The 0.96 cm² AVA_CTA threshold effectively identifies severe AS and performs well in validation.