Yunus Ahmed, Pieter A. J. van Bakel, Hechuan Hou, Devraj Sukul, Donald S. Likosky, Joost A. van Herwaarden, Daphne C. Watkins, Gorav Ailawadi, Himanshu J. Patel, Michael P. Thompson,
Abstract
Importance
Aortic stenosis (AS) is one of the most common heart valve conditions and its incidence and prevalence increases with age. With the introduction of transcatheter aortic valve replacement (TAVR), racial and ethnic disparities in AS diagnosis, treatment and outcomes is poorly understood.
Introduction
Aortic stenosis (AS) is one of the most common valvular heart diseases, disproportionately impacting older adults. An estimated 2–4% of patients over the age of 65 in the United States are diagnosed with AS, and its burden on public health and healthcare resources is expected to grow as the population age [1, 2]. Unlike mild to moderate AS, severe AS is associated with reduction in quality of life and life expectancy with medical management. The FDA approval of transcatheter aortic valve replacement (TAVR) in 2011 resulted in a paradigm shift in how severe AS is treated [3–8].
Despite these advances in treatment of AS, disparities in the management and treatment of AS are widely recognized and persistent [9]. Underrepresented minority populations, including Black-Americans, Hispanic-Americans, Asian-Americans and Pacific-Islanders, represent over 30% of the US population, but account for <10% of patients undergoing surgical aortic valve replacement (SAVR) or TAVR [10–12]. These disparities might be reflective of differential prevalence and incidence of AS among racial/ethnic minorities. On the other hand, racial/ethnic disparities in AS may be a result of underdiagnosis due to patient-level factors including patient social network, socioeconomic status, baseline health status, and cultural differences in addition to provider/health system factors including provider availability, hospital quality, and provider quality [13, 14]. These factors may lead to lower community stakeholder engagement and ultimately poor treatment access and quality outcomes for racial/ethnic minorities with AS. Among those patients diagnosed with AS, prior studies have found lower rates of specialist referral and interventions in racial/ethnic minorities, but comparable short- and long term outcomes [10, 15–19]. Establishing equitable outcomes in AS requires a better understanding of the current racial/ethnic disparities in the diagnosis and management of AS in the US. While racial disparities in AS care have been reported, they have not been investigated on a large scale, nor have the utilization of services based on the number of evaluation & management (E&M) visits.
Methods
Data sources
We obtained a nationally representative 20% sample of Medicare beneficiaries (n = 16,525,400) from the US Centers for Medicare & Medicaid Services, including the Medicare beneficiary summary, inpatient, outpatient, and carrier files from January 1, 2008 to December 31, 2019. The inpatient files contain institutional claims for inpatient services covered under Medicare Part A. Outpatient files contain institutional claims for outpatient services provided under Medicare Part B. Carrier files contain claims submitted by individual physicians. All files include service dates and International Classification of Diseases, Ninth Revision (ICD-9) or International Classification of Diseases, Tenth Revision (ICD-10) diagnosis and procedure codes. This study was deemed exempt from review by the University of Michigan Institutional Review Board.
Results
Diagnosis
A total of 1,513,455 patients diagnosed with AS (91.3% White, 4.5% Black, 1.1% Hispanic, 3.1% Asian and North American Native) were identified in the Medicare database between 2010 and 2018 (Table 1). Beneficiary demographics by year were reported in S2 Table. The AS incidence rate for the overall group increased from 13.5 to 17.0 per 1,000 beneficiaries between 2010 and 2018 (p<0.001, Fig 1). Racial/ethnic minorities had significantly lower incidence rates compared with White beneficiaries throughout the study period. The AS prevalence rate for the overall group increased from 33.5 to 40.0 per 1,000 beneficiaries between 2010 and 2018, (p<0.001). Again, racial/ethnic minorities had lower prevalence rates compared with White beneficiaries throughout the study period (p<0.001, Fig 1). Disparities in AS prevalence persisted after adjusting for age and sex; adjusted incidence rate ratios, aIRRs (95% CI), varied between 0.62 (0.60, 0.63) to 0.66 (0.65, 0.68) for Black beneficiaries, 0.71 (0.67, 0.74) to 0.67 (0.64, 0.70) for Hispanic beneficiaries and 0.73 (0.71, 0.76) to 0.75 (0.73, 0.77) for Asian and North American Native beneficiaries (all p<0.001).
Discussion
In this study we explored the role of race and ethnicity in AS using a population-based sample of Medicare beneficiaries in the United States. We found that racial and ethnic minorities were associated with significantly lower rates of incident and prevalent AS diagnoses compared with White beneficiaries. Once diagnosed with AS, cardiologist evaluations were comparable across all racial and ethnic groups, except for Asian and North American Native. In contrast, both evaluation by a cardiothoracic surgeon and treatment rates were markedly lower for minority populations compared with White patients. In addition, outcomes of all-cause hospitalizations, HF hospitalizations and 1-year mortality were worse for Black patients compared with White patients. Collectively, these findings suggest that racial and ethnic disparities are present across the continuum of AS diagnosis, management, and outcomes.
Conclusion
In conclusion, we demonstrated that racial and ethnic minorities were significantly less frequently diagnosed with AS and had disparities in both adequate management and outcomes in a population-based cohort of Medicare beneficiaries. While the etiology of these findings remains unclear, the driving factors leading to these disparities will need further evaluation to address this pathology equitably across demographic groups.
Citation: Ahmed Y, van Bakel PAJ, Hou H, Sukul D, Likosky DS, van Herwaarden JA, et al. (2023) Racial and ethnic disparities in diagnosis, management and outcomes of aortic stenosis in the Medicare population. PLoS ONE 18(4): e0281811. https://doi.org/10.1371/journal.pone.0281811
Editor: R. Jay Widmer, Baylor Scott and White, Texas A&M College of Medicine, UNITED STATES
Received: April 29, 2022; Accepted: February 1, 2023; Published: April 10, 2023
Copyright: © 2023 Ahmed et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the paper and its Supporting Information file.
Funding: The author(s) received no specific funding for this work.
Competing interests: The authors have declared that no competing interests exist.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0281811#sec021
