Tweet summarizing research:
“At MESA Exam 6, the age-adjusted prevalence of AS is lower in Black (1.8%) and Chinese (0.3%) compared to Hispanic (3.7%) and White participants (3.5%).”
Keywords: Aortic stenosis, aortic valve replacement, race, ethnicity, inequity, disparity
Although long present, racial/ethnic disparities in cardiovascular care are increasingly recognized. A study of >32,000 patients with severe symptomatic aortic stenosis (AS) found Black patients were less likely than White patients to undergo aortic valve replacement (AVR).(1) In their study utilizing a large clinical echocardiographic database, Patel et al. found an overall prevalence of severe AS of 0.29% in Black patients and 0.91% in White patients.(2) However, these and other studies are limited by selection bias and a lack of data/power for races/ethnicities other than Black and White. Understanding and addressing inequities in the treatment of AS requires an understanding of possible racial/ethnic differences in the prevalence of AS.
The Multi-Ethnic Study of Atherosclerosis (MESA) enrolled 6,814 participants aged 45–84 without clinical cardiovascular disease at six centers in the United States from 2000 to 2002 (Exam 1). Transthoracic echocardiography was performed for 3032/3303 (91.8%) of participants attending Exam 6 (2016–2018). Studies were read at the MESA Echocardiography Reading Center at Northwestern University by two clinical cardiologists who determined the presence of mild or greater AS according to American Society of Echocardiography guidelines.(3) This study was approved by each institution’s Institutional Review Board; all participants provided written informed consent.
Of the 3032 participants who completed echocardiography, 761 (25.1%) were Black, 407 (13.4%) Chinese, 657 (21.7%) Hispanic, and 1207 (39.8%) White. The median age was 73 years (interquartile range [IQR] 67–80 years) without a significant difference by race/ethnicity, and 47.0% were male. White and Black participants had the highest prevalence of prior rheumatic heart disease by history (3.9% and 3.4%, respectively); Black participants had the highest lipoprotein(a) mass concentration (median 35.1 mg/dl, IQR 20.0–63.3) at Exam 1. Death was the most common reason for missed exam 6 echocardiography (41.0% of the 3,763 Exam 1 participants without an echocardiogram and with known death status) and the proportion not attending due to death differed by race/ethnicity (44.1% for Black, 36.6% for Chinese, 35.3% for Hispanic, and 43.2% for White; p <0.001).
Seventy-seven participants had AS on echocardiography, with 29 mild AS (37.7%) and 48 (62.3%) moderate or greater AS, and 22 had AVR. Standardized to the age structure of all MESA participants at Exam 6, the age-adjusted prevalence of AS was highest in White (3.5%) and Hispanic participants (3.7%), while Black (1.8%), and Chinese participants (0.3%) had a lower prevalence (Table). Among participants with AS, there were no differences in measures of AS severity by race/ethnicity (Table). After multivariable adjustment by logistic regression for Exam 1 differences in demographics, comorbidities, smoking, lipid profile, kidney function, and medications, Black (odds ratio [OR] 0.47, 95% CI 0.22–1.00, p=0.05) and Chinese race/ethnicity (OR 0.09, 95% CI 0.01–0.70, p=0.02) were associated with a lower odds of AS compared to White race/ethnicity, while Hispanic race/ethnicity was not (OR 1.01, 95% CI 0.56–1.82, p=0.98). Compared to White race/ethnicity, Black (OR 0.32, 95% CI 0.16–0.64, p=0.001) and Chinese (OR 0.15, 95% CI 0.03–0.64, p=0.01) but not Hispanic race/ethnicity (OR 1.01, 95% CI 0.59–1.73, p=0.96) were also associated with a lower odds of the composite of AS/AVR.
Table.
Prevalence and severity of aortic stenosis and aortic valve replacement by echocardiography.
| Black | Chinese | Hispanic | White | Overall* | P-value | |||
|---|---|---|---|---|---|---|---|---|
| n = 761 | n = 407 | n = 657 | n = 1207 | Black-White† | Chinese-White† | Hispanic-White† | ||
| AS‡ | ||||||||
| n | 13 | 1 | 22 | 41 | - | - | - | - |
| Crude prevalence | 1.7 (1.0–2.9) | 0.3 (0.03–1.7) | 3.4 (2.2–5.0) | 3.4 (2.5–4.6) | 0.001 | 0.03 | <0.001 | 0.96 |
| Age-adjusted prevalence | 1.8 (1.1–3.1) | 0.3 (0.04–2.0) | 3.7 (2.5–5.6) | 3.5 (2.6–4.7) | 0.001 | 0.04 | <0.001 | 0.82 |
| AVA§ (cm2)|| | 1.46 (1.30–1.61) | - | 1.47 (1.09–1.56) | 1.35 (1.18–1.58) | 0.70 | - | - | - |
| AVAi# (cm2/m2)|| | 0.81 (0.65–0.85) | - | 0.76 (0.60–0.82) | 0.72 (0.62–0.85) | 0.68 | - | - | - |
| Doppler velocity index|| | 0.42 (0.36–0.47) | - | 0.42 (0.31–0.46) | 0.41 (0.32–0.50) | 0.95 | - | - | - |
| AVR** | ||||||||
| n | 2 | 1 | 9 | 10 | - | - | - | - |
| Crude prevalence | 0.3 (0.1–1.1) | 0.3 (0.03–1.7) | 1.4 (0.7–2.6) | 0.8 (0.5–1.5) | 0.06 | - | - | - |
| Age-adjusted prevalence | 0.3 (0.1–1.1) | 0.3 (0.04–2.0) | 1.4 (0.7–2.7) | 0.8 (0.5–1.6) | 0.06 | - | - | - |
| AS‡ or AVR** | ||||||||
| n | 15 | 2 | 31 | 51 | - | - | - | - |
| Crude prevalence | 2.0 (1.2–3.2) | 0.5 (0.1–1.9) | 4.7 (3.3–6.6) | 4.2 (3.2–5.5) | <0.001 | 0.007 | <0.001 | 0.63 |
| Age-adjusted prevalence | 2.1 (1.3–3.4) | 0.6 (0.2–2.2) | 5.1 (3.6–7.2) | 4.3 (3.3–5.7) | <0.001 | 0.009 | <0.001 | 0.47 |
All prevalence values are % (95% confidence interval).
Overall P-values are for the comparison between all four racial/ethnic groups by the Chi-Square test for prevalence estimates and the Kruskal-Wallis test for indices of aortic stenosis severity.
P-values for pairwise comparisons between groups are for the Wald test with adjustment for multiple comparisons by Holm’s method.
Aortic stenosis.
Aortic valve area.
n = 76.
Aortic valve area indexed to body surface area.
Aortic valve replacement.
We found a lower prevalence of AS in Black and Chinese compared to White and Hispanic individuals. Our findings are consistent with those of Patel et al. and build upon their results by 1) extending to a sample without clinically-indicated echocardiography, which selects those with access to medical care, and 2) including Chinese and Hispanic participants. Limitations include lack of data regarding indications for AVR and differential death rates according to race/ethnicity which could bias our results. Furthermore, exclusion of participants with clinical cardiovascular disease at baseline likely resulted in underestimation of true AS prevalence. Additionally, while the MESA sample is not representative of the overall population of the United States, it was selected to be racially/ethnically diverse and enable observations such as those reported herein.
In this multi-ethnic cohort, Black and Chinese participants had a lower prevalence of AS compared with White participants, while Hispanic participants had a similar prevalence. Additional studies are needed to validate our findings in other populations, assess for pathophysiologic mechanisms underpinning these differences, and determine if the observed racial/ethnic differences in AS prevalence may partially account for previously observed differential rates of surgical or transcatheter AVR.
Acknowledgments:
The authors thank the other investigators, the staff, and the participants of the MESA study for their valuable contributions. A full list of participating MESA investigators and institutions can be found at http://www.mesa-nhlbi.org.
Funding:
This research was supported by contracts 75N92020D00001, HHSN268201500003I, N01-HC-95159, 75N92020D00005, N01-HC-95160, 75N92020D00002, N01-HC-95161, 75N92020D00003, N01-HC-95162, 75N92020D00006, N01-HC-95163, 75N92020D00004, N01-HC-95164, 75N92020D00007, N01-HC-95165, N01-HC-95166, N01-HC-95167, N01-HC-95168 and N01-HC-95169 from the National Heart, Lung, and Blood Institute (NHLBI), and by grants UL1-TR-000040, UL1-TR-001079, and UL1-TR-001420 from the National Center for Advancing Translational Sciences (NCATS) and the MESA Early Heart Failure Study (NHLBI R01HL127028). Research reported in this publication was supported by the National Research Service Award of the National Institutes of Health T32HL007227.
Disclosures:
SJS has received research grants from Actelion, AstraZeneca, Corvia, Novartis, and Pfizer; and has received consulting fees from Abbott, Actelion, AstraZeneca, Amgen, Axon Therapies, Bayer, Boehringer-Ingelheim, Bristol-Myers Squibb, Cardiora, CVRx, Cytokinetics, Eisai, GSK, Ionis, Ironwood, Lilly, Merck, MyoKardia, Novartis, Novo Nordisk, Pfizer, Prothena, Regeneron, Sanofi, Shifamed, Tenax, and United Therapeutics. The other authors have no disclosures or relationships with industry relevant to the content of this manuscript.
Abbreviations List
- AS
aortic stenosis
- AVA
aortic valve area
- AVAi
aortic valve area indexed to body surface area
- AVR
aortic valve replacement
- CI
confidence interval
- IQR
interquartile range
- MESA
Multi-Ethnic Study of Atherosclerosis
- OR
odds ratio
Footnotes
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References
- 1.Brennan JM, Leon MB, Sheridan P et al. Racial differences in the use of aortic valve replacement for treatment of symptomatic severe aortic valve stenosis in the transcatheter aortic valve replacement era. J Am Heart Assoc 2020;9:e015879. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Patel DK, Green KD, Fudim M, Harrell FE, Wang TJ, Robbins MA. Racial differences in the prevalence of severe aortic stenosis. J Am Heart Assoc 2014;3:e000879. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Baumgartner H, Hung J, Bermejo J et al. Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice. J Am Soc Echocardiogr 2009;22:1–23. [DOI] [PubMed] [Google Scholar]