Assessing Reporting of Low-Gradient Severe Aortic Stenosis Based on Race and Ethnicity: Observations from a Large Academic Health System

Introduction: Though low-gradient (LG) aortic stenosis (AS) is common and frequently reported as non-severe on transthoracic echocardiogram (TTE) in real world practice, the association of race and ethnicity with LG AS type and reported severity is not well understood. Methods: We identified all adults ≥ 18 years old from 9/2015-11/2019 with AS, aortic valve area < 1.0cm 2 , and mean gradient <40mmHg on TTE within a large academic health system. We determined frequency of LG AS type (classical low-flow LG [CLFLG], paradoxical low-flow LG [PLFLG], and normal-flow LG [NFLG]) by race and ethnicity. We assessed whether race and ethnicity were associated with reporting severe-range AS on TTE using multivariable logistic regression accounting for age, sex, body mass index, mean gradient, aortic valve area, AS type, and quaternary vs. non-quaternary TTE site. Results: Among 2740 adults with LG AS, 92.4% were white, 4.3% were black, and 3.7% were Hispanic. PLFLG AS was the most common LG AS type among white and black patients and the least common among Hispanic patients (Figure). Among those with PLFLG AS, black patients had the highest proportion of TTEs reported as severe-range AS, while Hispanic patients had the lowest; there were no differences in reporting for CLFLG or NFLG AS (Figure). After multivariable adjustment, there were no significant differences in reporting severe-range AS based on black race (adjusted OR 1.63, 95% CI 0.95-2.82) or Hispanic ethnicity (adjusted OR 1.05, 95% 0.39-2.75) compared to white patients. Quaternary site was a strong independent predictor of reporting severe-range AS (adjusted OR 4.97, 95% CI 3.81-6.54). Conclusions: There are race- and ethnicity-based differences in frequency of LG AS type, and in reporting severe AS on TTE for PLFLG AS in particular. Differences in reporting for PLFLG AS are attenuated after accounting for factors such as TTE site. Additional factors influencing reporting of LG AS in real-world practice should be investigated.