Discrepancies between direct catheter and echocardiography-based values in aortic stenosis.

Objectives: The goal of this article is to examine the correlation of catheter (cath) based and echocardiographic assessment of aortic stenosis (AS) in a community-based academic hospital setting, particularly in the degree that decision to refer for surgery is altered.

Background: Current guidelines discourage AS evaluation by invasive pressure measurement if echocardiography (echo) is adequate, but several studies show sizable differences between echo and cardiac catheterization lab (CCL) measurements. We examine this correlation using high quality CCL techniques.

Methods: Sequential patients with suspected AS by echo (n = 40) aged 61-94 underwent catheterization with pressure gradients via left ventricular pressure wire and ascending aorta catheter. The echos leading to the catheterization were independently reviewed by an expert panel to assess the quality of community-based readings.

Results: CCL changed assessment of severity of aortic valve area (AVA) by more than 0.3 cm(2) in 25% and 0.5 cm(2) in 8%. Values changed to over or under the surgical threshold of AVA < 1 cm(2) in 30% of the patients. Pearson correlation of 0.35 between measurements of AVA by echo and CCL is lower than earlier studies, which often reported correlation values of 0.90 or greater. Echo expert reviews provided minimal improvement in discrepancies (Pearson correlation of 0.46), suggesting quality of initial interpretation was not the issue.

Conclusions: Cath-echo correlation of AS severity is lower in contemporaneous practice than previously assumed. This can alter the decision for aortic valve replacement. Sole reliance on echo-derived assessment of AS may at times be problematic.