Differential left ventricular outflow tract remodeling and dynamics in aortic stenosis

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Mechanics

Background:

• Left ventricular outflow tract (LVOT) geometry is variable and often elliptical in aortic stenosis (AS) patients, potentially affecting aortic valve area calculation.
• Differences in LVOT geometry and dynamics between AS patients and controls are not well-described.
• This study investigated LVOT remodeling and stiffness in AS patients compared to controls.

Purpose of the Study:

• To test the hypothesis that LVOT geometry differences in AS patients relate to variable LVOT remodeling and stiffness.
• To compare LVOT geometry, dynamics, remodeling, and stiffness between severe AS patients and normal controls.

Main Methods:

• Three-dimensional transesophageal echocardiography was used to assess LVOT geometry, dynamics, remodeling, and stiffness in 54 AS patients and 33 controls.
• LVOT stiffness was quantified by the distensibility coefficient; remodeling by posterior LVOT wall thickness.
• Multivariate linear regression identified factors associated with peak systolic LVOT ellipticity.

Main Results:

• Patients with AS showed reduced cross-sectional area change during systole and higher peak systolic ellipticity compared to controls.
• AS patients had significantly lower distensibility coefficients and increased posterior LVOT wall thickness.
• Posterior LVOT wall thickness and distensibility coefficient were independently associated with peak systolic LVOT ellipticity.

Conclusions:

• The LVOT in severe AS is less distensible and undergoes remodeling.
• These changes result in greater peak systolic ellipticity and underestimation of LVOT area.
• Findings highlight the importance of considering LVOT remodeling and stiffness in AS severity assessment.