Doppler Underestimates Transvalvular Gradient Measured by Catheterization in Patients With Severe Aortic Stenosis

Area of Science:

• Cardiology
• Medical Imaging
• Echocardiography

Background:

• Severe aortic stenosis (AS) is a critical condition requiring accurate hemodynamic assessment.
• Doppler echocardiography is a primary tool for assessing AS severity, but potential underestimation of the pressure gradient exists.
• Catheterization provides a gold standard for pressure gradient measurement, but is invasive.

Purpose of the Study:

• To identify patient characteristics associated with underestimation of transvalvular mean pressure gradient (MPG) by Doppler echocardiography compared to catheterization in severe AS.
• To assess the clinical implications of Doppler underestimation on AS severity classification and treatment guidance.

Main Methods:

• Retrospective analysis of 127 severe AS patients undergoing transcatheter aortic valve implantation.
• Comparison of Doppler-derived MPG with catheterization-derived MPG.
• Evaluation of echocardiographic parameters including relative wall thickness and aortic valve calcification score (Agatston method).

Main Results:

• 21% of patients showed significant Doppler MPG underestimation (≥10 mm Hg).
• Underestimation was associated with higher relative wall thickness and increased aortic valve calcification.
• Doppler underestimation could misclassify patients, potentially delaying valve replacement indications.

Conclusions:

• Heavy aortic valve calcification and prominent concentric left ventricular remodeling are independently associated with Doppler underestimation of MPG in severe AS.
• Sole reliance on Doppler MPG may lead to clinical misjudgments in AS management.
• Consideration of patient-specific factors like calcification and ventricular geometry is crucial for accurate AS assessment.