Progression of aortic stenosis and echocardiographic criteria for its severity

Abstract

Aims Guidelines-recommended criteria for identifying severe aortic stenosis (AS) are based on small, homogenous cohorts of patients, leading to potentially inconsistent or missed diagnosis. We used a large cohort of patients with varying degrees of AS to (i) characterize its progression; (ii) evaluate the influence of demographic and echocardiographic variables; and (iii) derive haemodynamically consistent cut-off values. Methods and results We identified 916 patients with mild to severe AS who had undergone >1 echocardiographic study (N = 2547). For each study, aortic valve area (AVA), peak transaortic velocity (Vmax), and mean pressure gradient (ΔP) were extracted. Annual rates of AVA change were determined by a linear mixed-effects model. To determine the prevalence of inconsistent diagnosis of severe AS, AVA was plotted against ΔP and Vmax, with quadrants defined using guidelines-recommended cut-offs. The rate of AVA change was −0.070 ± 0.003 cm2/year and was more rapid in men than women and in Whites than African Americans. AVA = 1 cm2 corresponded to ΔP = 32 mmHg and Vmax = 3.7 m/s, causing discrepancies in defining severe AS in 480 (19%) and 458 (18%) studies, respectively. Conversely, ΔP = 40 mmHg corresponded to AVA = 0.89 cm2 and Vmax = 4.0 m/s corresponded to AVA = 0.92 cm2, confirming the inconsistency of the guidelines. Notably, discrepancy rate was higher in 206 patients with low flow (SVi < 35 mL/m2): 40% vs. 16% in the remaining patients. Conclusion Our findings demonstrated gender- and race-related differences in AS progression and underscored the need to refine the multiparametric criteria for diagnosis of severe AS to minimize internal inconsistencies, which are high with the current cut-offs and amplified in patients with low stroke volumes.

Aortic valve area calculation using 3D transesophageal echocardiography: Implications for aortic stenosis severity grading

“…In nearly 75% of those with low‐flow states by 2D‐TTE, a normal SV was calculated using 3D‐TEE methods. The analysis of the fitted curves for data pairs AVA and MPG confirmed that 2D‐TTE AVA overestimates the severity of AS, with a an AVA of 1 cm 2 being related to a MPG well below the 40 mm Hg cutoff reported in current guidelines, in line with previously reported data 5,19 . Similarly to what observed with MDCT, both 3D‐TEE imaging modalities showed a reduction in the proportion of patients with low‐gradient and pathological AVA, as well as better agreement between AVA and MPG with current guidelines cutoff values.…”

Moderate aortic stenosis: culprit or bystander?

“…Disease progression was also found to occur more rapidly in Caucasians than African Americans (decrease in AVA cm 2 /year 0.075±0.005 in Caucasians vs 0.062±0.004 in African Americans, p=0.03). This finding may be attributable to the higher prevalence of bicuspid aortic valve in Caucasians than in the general population 23…”

“…In a 1997 prospective study by Otto et al, 20 123 patients with asymptomatic mild to moderate AS followed for 2–3 years had an annual increase in Vmax of 0.32±0.34 m/s, increase in MPG of 7±7 mm Hg and decrease in AVA of 0.12±0.19 cm 2 /year. More recent studies suggest a slower annual progression of AS with Vmax increase of 0.24±0.3 m/s, increase in MPG of 3.2–6.4 mm Hg and decrease in AVA of 0.068±0.004 cm 2 /year 5 20–23…”

“…Certain demographic features also associate with the rapidity of AS progression. Recent data suggest that progression may be faster in men than in women (decrease in AVA cm 2 /year 0.078±0.004 in men vs 0.065±0.004 in women, p=0.02) 1 23. Disease progression was also found to occur more rapidly in Caucasians than African Americans (decrease in AVA cm 2 /year 0.075±0.005 in Caucasians vs 0.062±0.004 in African Americans, p=0.03).…”

“…This finding may be attributable to the higher prevalence of bicuspid aortic valve in Caucasians than in the general population. 23 …”