The impact of underdiagnosis and delay in care for patients with moderate and severe aortic stenosis: A real-world database cohort study

Background Despite advances in diagnostic capabilities and therapeutic options for aortic stenosis (AS), evidence suggests substantial underdiagnosis and care delays in real-world practice. This study examines patterns and disparities in AS diagnosis following echocardiographic identification, quantifying delays in diagnosis and subsequent care. Methods Using the Optum® Market Clarity Dataset (2016–2023), we identified patients with first echocardiographic evidence of moderate or severe AS. Time-to-event analyses examined delays between echocardiographic findings and formal diagnosis (defined by ICD code assignment), subsequent imaging, and interventions. Analyses were stratified by severity, demographics, and care setting. Results Among 2366 moderate and 1327 severe AS patients, 22.0% and 38.3% received formal diagnoses within one year of echocardiogram, respectively. Cumulative incidence of AS diagnosis at one year was lower in women vs men (moderate: 17.3% vs 27.8%; severe: 33.8% vs 43.0%) and non-White vs White patients (moderate: 11.4% vs 24.6%; severe: 25.8% vs 40.4%; all P ≤ 0.0001). Formal diagnosis was associated with increased likelihood of subsequent care (composite of follow-up imaging or aortic valve replacement) (moderate AS: HR 1.68, P < 0.0001; severe AS: HR 2.25, P < 0.0001). Conclusions This analysis reveals substantial delays in formal ICD-coded AS diagnosis following its echocardiographic detection, with concerning disparities across demographic groups. These findings suggest gaps between clinical recognition and formal documentation of AS, with implications for care continuum. Clinical perspectives What Is New? • Using a large, real-world integrated claims and EMR database, this study demonstrates that fewer than one-quarter of patients with echocardiographically confirmed moderate AS and fewer than 40% with severe AS receive a formal ICD-coded diagnosis within one year, with substantially lower rates among women and non-White patients. What Are the Clinical Implications? • These findings reveal a critical gap between echocardiographic detection of AS and formal clinical documentation, suggesting that administrative claims data alone may substantially underestimate the true burden of AS in the population. • Formal AS diagnosis was independently associated with a significantly higher likelihood of receiving subsequent care — including surveillance imaging and aortic valve replacement — underscoring that closing the documentation gap may be a meaningful lever for improving outcomes and reducing disparities in AS management.