Tracking progression of aortic stenosis with echocardiography

Area of Science:

• Cardiology
• Medical Imaging
• Echocardiography

Background:

• Transthoracic echocardiography (TTE) is crucial for assessing aortic stenosis (AS) severity and progression.
• Reliable non-invasive imaging markers are needed for clinical trials evaluating medical therapies for AS.
• The signal-to-noise ratio of TTE measures for progressive, non-severe AS is not well-established.

Purpose of the Study:

• To evaluate the signal-to-noise ratio of commonly used TTE-based hemodynamic markers for assessing progressive (non-severe) aortic stenosis.
• To determine the most reliable TTE marker for tracking disease progression in patients with non-severe AS.

Main Methods:

• Retrospective analysis of TTEs from a tertiary referral center.
• Inclusion of two patient cohorts: those with TTEs within 30 days (reproducibility) and those with TTEs ≥1 year apart (progression), without intervention.
• Calculation of limits of agreement (LOA), intraclass correlation (ICC), and Cohen's d-statistic for aortic valve area (AVA), peak velocity, and mean gradient.

Main Results:

• The progression cohort included 35 patients with a median follow-up of 2.2 years.
• Intraclass correlation coefficients (ICC) indicated poor agreement for peak velocity (0.29) and mean gradient (0.06) in the reproducibility cohort.
• Cohen's d-statistic for annualised change showed the highest value for mean gradient (0.55), followed by peak velocity (0.46) and AVA (-0.29).

Conclusions:

• Standard TTE markers exhibit variable sensitivity in detecting AS progression.
• Mean gradient demonstrates the highest signal-to-noise ratio among assessed TTE markers for progressive, non-severe AS.
• Mean gradient may be the most dependable TTE-based assessment for monitoring disease progression in this patient group.