“overestimation” of catheter gradients by doppler ultrasound in patients with aortic stenosis: a predictable manifestation of pressure recovery
Key result
Doppler gradients corrected for pressure recovery closely match catheter measurements, avoiding significant overestimation.
- n=23
Why the study?
Pressure recovery causes discrepancy between Doppler and catheter gradients in vitro, but its clinical relevance in patients with aortic stenosis was not evaluated.
Does correcting for pressure recovery improve the agreement between Doppler echocardiography and catheter gradients in patients with aortic stenosis?
Comparison
Doppler gradients (noncorrected and corrected for pressure recovery) vs catheter gradients
Design
Comparative observational study
Authors
Discussion
Loading...
Member takes
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“For accurate assessment of aortic stenosis severity by echocardiography/Doppler, the aortic valve area must be adjusted for energy recovery and calculated as energy loss index.”
Implication
Pressure recovery may explain Doppler-catheter discrepancies in AS; leaves open whether routine correction alters management or outcomes.
Key Points
- To evaluate whether pressure recovery explains the discrepancies between Doppler and catheter gradients in patients with aortic stenosis, and whether these differences can be predicted using Doppler echocardiography.
- Studied 23 patients with various degrees of aortic stenosis using Doppler echocardiography and catheterization techniques within 24 hours.
- Calculated pressure recovery from peak transvalvular velocity, aortic valve area, and ascending aorta cross-sectional area to correct Doppler gradients for comparison against catheter measurements.
- Predicted pressure recovery correlated strongly with observed Doppler-catheter differences for peak (r = 0.90; predicted 19 ± 16 mm Hg vs. observed 18 ± 18 mm Hg) and mean gradients (r = 0.85; predicted 12 ± 11 mm Hg vs. observed 11 ± 13 mm Hg).
- Uncorrected Doppler gradients significantly overestimated catheter gradients (slope 1.36 for peak, 1.25 for mean), whereas corrected Doppler gradients aligned closely with catheter values (slope 1.03, mean difference 0.4 ± 8.0 mm Hg for peak; slope 0.96, mean difference 1.1 ± 6.8 mm Hg for mean).
Study Design
Type
Observational (n=23)
Structured PICO
Does correcting for pressure recovery improve the agreement between Doppler echocardiography and catheter gradients in patients with aortic stenosis?
P
Population
23 patients with various degrees of aortic stenosis evaluated with Doppler echocardiography and catheter technique within 24 hours.
E
Exposure
Doppler echocardiography with correction for predicted pressure recovery (estimated from peak transvalvular velocity, aortic valve area, and cross-sectional area of the ascending aorta)
C
Comparator
Invasive catheter gradients and noncorrected Doppler gradients
O
Outcome
Agreement between Doppler and catheter gradientssurrogate
Correcting Doppler echocardiography gradients for pressure recovery significantly improves their agreement with invasive catheter gradients in patients with aortic stenosis.
Cite This Study
Baumgartner et al. (1999) conducted an observational in aortic stenosis (n=23). Doppler echocardiography corrected for pressure recovery vs. catheter technique was evaluated on Difference between Doppler and catheter gradients. Doppler gradients corrected for pressure recovery showed good agreement with catheter gradients (mean difference 0.4 +/- 8.0 mm Hg for peak gradients), avoiding significant overestimation.