Research Highlights:
- An analysis of more than two million adults in the U.S. found that present day heart failure risk was higher among Black adults who lived in zip codes historically impacted by redlining compared to Black adults living in non-redlined areas.
- Redlining did not have the same impact on heart failure risk among white adults living in historically redlined zip codes.
- Among Black adults living in historically redlined communities, approximately half of the excess risk of heart failure appeared to be explained by higher levels of socioeconomic distress.
DALLAS, July 17, 2023 — The risk of heart failure in the present day was higher among Black adults who lived in U.S. zip codes historically impacted by redlining, according to research published today in the American Heart Association’s flagship, peer-reviewed journal Circulation. The analysis, published as part of the journal’s “Disparities in Cardiovascular Medicine Special Issue,” included more than 2.3 million adults from 2014-2019 who lived in U.S. communities with varying degrees of redlining, which began in the mid-1930s.
In 1933, the Home Owners’ Loan Corporation, a government agency created as part of President Roosevelt’s New Deal, began sponsoring low-interest mortgage loans to help people recover from the financial crisis of the Great Depression. In a process called “redlining,” the HOLC developed a color-coding system for neighborhoods across the country based on “risk for investment” criteria; it deemed red areas, which were largely Black communities, “too risky” to insure mortgages. The residents who lived in these neighborhoods were denied home loans, which lowered tax revenues in these communities and reduced investment in schools and government programs and services. This created numerous inequities for residents for multiple generations despite the practice being outlawed by the Fair Housing Act of 1968.
Previous research has found that communities exposed to redlining had higher rates of stroke, as well as increased risk of hypertension, Type 2 diabetes and early mortality due to heart disease. Heart failure is a progressive condition in which the heart is unable to pump enough blood to the body either due to the heart muscle stiffening or from it losing pumping strength. According to the American Heart Association’s 2023 Statistical Update, heart failure affects 6.7 million people in the U.S. and disproportionately impacts Black adults.
“Although discriminatory housing policies were effectively outlawed nearly a half-century ago, the relationship between historic redlining practices and people’s health today gives us unique insight into how historical policies may still be exerting their effects on the health of many communities,” said study co-senior author Shreya Rao, M.D., M.P.H., a cardiologist and assistant professor in the department of internal medicine at the University of Texas Health Science Center at San Antonio and University Hospital, both in San Antonio, Texas.
The researchers identified nearly 2.4 million adults in the Medicare Beneficiary Summary Files between 2014 and 2019 with linked residential zip codes. Study participants were 55.4% female and had a mean age of 71 years; 801,452 of participants self-identified as Black adults, and nearly 1.6 million participants self-identified as non-Hispanic white adults. Individuals of other races were excluded due to the low numbers available within the Medicare data. Participants were excluded from the analysis if they had a history of heart failure or heart attack in the preceding two years, had fewer than two years of Medicare coverage before the study start date or were younger than the age of 40.
The researchers mapped historical redlining maps onto modern day maps of 1,044 zip codes in the U.S. and sorted them into four groups ranging from zip codes that had the least amount of area impacted by redlining to zip codes with the most areas exposed to redlining.
“Ultimately, we were most interested in assessing the difference in risk of heart failure between individuals from communities with the highest level of exposure to redlining and individuals from other communities,” said first author Amgad Mentias, M.D., M.S., an interventional cardiology fellow at Cleveland Clinic in Cleveland, Ohio.
The researchers assessed the association between living in higher proportions of redlined zip codes and heart failure risk. They conducted separate analyses for Black and white adults and additional variables were considered, such as social determinants of health, which were determined at the zip-code level with Social Deprivation Index scores collected in the American Community Survey from 2011-2015. The Social Deprivation Index is a composite measure based on seven demographic characteristics collected in the American Community Survey, including poverty rate, education level, employment, access to transportation, household characteristics (single-parent households), percentage of households that rent rather than own housing, and percentage of households that are overcrowded. Heart failure was identified as hospitalization with a primary diagnosis of heart failure. Although most adults qualify for Medicare at 65 years old, the cohort also included adults younger than 65 who qualified for Medicaid due to disability.
The analysis found:
- Black adults living in zip codes with the highest proportion of redlining had an 8% higher risk of developing heart failure compared to Black adults living in communities with low levels of redlining.
- In contrast, white adults living in zip codes with the highest proportion of redlining did not have an increased risk of heart failure.
- About half of the excess risk of heart failure among Black adults living in redlined communities was explained by higher levels of socioeconomic distress (determined by Social Deprivation Index scores) in those redlined communities.
- The risk of heart failure was highest in Black adults living in redlined communities that had high scores on the Social Deprivation Index.
“These findings show us the harm that discriminatory and racist housing policies have had on generations of Black adults and suggest the long-term impact of such policies on cardiovascular health disparities,” said senior author Ambarish Pandey, M.D., M.S., a cardiologist and assistant professor in the department of internal medicine at the University of Texas Southwestern Medical Center in Dallas. “A reparative approach may be needed on the part of federal, state and local governments to intervene and drive investment in redlined communities.”
The findings also highlight the pivotal role housing plays as a social determinant of health, Pandey noted. “Aggressive enforcement of anti-discrimination laws in housing, and support for and pathways to homeownership for Black families are needed in order to begin to achieve equity in health, ” he said.
The study’s limitations include that redlining is just one facet of the impact of discrimination in the U.S. Redlining does not, alone, capture the full contribution of systemic racism on health today, the authors noted.
“Decades of discriminatory housing policies have left a lasting imprint on the cardiovascular health of Black communities. This careful and systematic analysis underscores the higher heart failure risk faced by Black adults residing in historically redlined areas, and provides evidence that social determinants of health, such as poverty, education, and access to healthy food, drive this risk,” said the American Heart Association’s Chief Clinical Science Officer Mitchell Elkind, M.D., M.S., FAHA, FAAN. “The study serves as a stark reminder of the ongoing impact of structural racism and emphasizes the urgent need for restorative actions and targeted investments to promote health equity.”
Co-authors are Mahasin S. Mujahid, Ph.D., FAHA; Andrew Sumarsono, M.D.; Robert K. Nelson, Ph.D.; Justin M. Madron, Ph.D.; Tiffany M. Powell-Wiley, M.D., M.P.H., FAHA; Utibe R. Essien, M.D., M.P.H.; Neil Keshvani, M.D.; Saket Girotra, M.D., S.M.; Alanna A. Morris, M.D., M.Sc., FAHA; Mario Sims, Ph.D., FAHA; Quinn Capers IV, M.D.; Clyde Yancy, M.D., M.Sc., FAHA; Milind Desai, M.D., M.B.A., FAHA; and Venu Menon, M.D., FAHA. Authors’ disclosures are listed in the manuscript.
The study was funded by the Haslam Family, Bailey Family and Khouri Family to the Cleveland Clinic, as well as the National Institute on Aging and the National Institute on Minority Health and Disparities, both of which are divisions of the National Institutes of Health.
The Disparities in Cardiovascular Medicine Special Issue of Circulation also includes a separate study examining historical neighborhood redlining and cardiovascular risk in patients with chronic kidney disease. In this study, researchers at Case Western Reserve University analyzed data for 1,720 participants enrolled in the Chronic Renal Insufficiency Cohort in 2003-2008. The analysis found that people with mild to moderate chronic kidney disease who lived in historically redlined neighborhoods had a two-fold higher risk of developing heart failure, independent of major risk factors for cardiovascular disease.
Additional research publishing in the special issue includes:
- Historical Neighborhood Redlining and Cardiovascular Risk in Patients with Chronic Kidney Disease; Al-Kindi et al.
- Associations between Maternal Sociodemographics and Hospital Mortality in Newborns with Prenatally Diagnosed Hypoplastic Left Heart Syndrome; Lopez et al.
- Racial Disparities in Exposure to Ambient Air Pollution During Pregnancy and Prevalence of Congenital Heart Defects; Arogbokun Knutson et al.
- Arrhythmia and Survival Outcomes among Black and White Patients with a Primary Prevention Defibrillator; Goldenberg et al.
- Racial differences in quality of life in patients with heart failure treated with sodium-glucose cotransporter 2 inhibitors: A patient-level meta-analysis of the CHIEF-HF, DEFINE-HF, and PRESERVED-HF trials; Lanfear et al.
- Race-based differences in ST elevation myocardial infarction (STEMI) process metrics and mortality from 2015-2021: an analysis of 178,062 patients from the American Heart Association Get With The Guidelines-Coronary Artery Disease (GWTG-CAD) Registry; Goyal et al.
- Socioeconomic disparities and mediators for recurrent atherosclerotic cardiovascular disease events after a first myocardial infarction; Ohm et al.
Statements and conclusions of studies published in the American Heart Association’s scientific journals are solely those of the study authors and do not necessarily reflect the Association’s policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers and the Association’s overall financial information are available here.
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ARTICLE TITLE
Historical Redlining, Socioeconomic Distress, and Risk of Heart Failure Among Medicare Beneficiaries
Black patients with implantable cardioverter defibrillators (ICDs) have a significantly higher burden of disease than white patients with the same device, according to a new study from University of Rochester Medical Center (URMC) cardiology researchers. Analyzing data from clinical trials conducted over a 20-year period by the Clinical Cardiovascular Research Center (CCRC) at URMC, investigators concluded that not only did Black patients with ICDs tend to be significantly younger than white patients, but they also had a higher rate of post-implant cardiac events and risk of death.
When a patient is at risk for cardiac arrest, an ICD helps to monitor their heart rhythm, and if an abnormality is detected, the device delivers a shock of electricity to reset the heartbeat to a normal rhythm. The study, published in Circulation, examines the rate of events that a patient experiences after their ICD is implanted. After three years of monitoring, the risk of ventricular arrhythmia (sustained rapid heartbeat that can lead to sudden cardiac death) was 20 percent for white patients, but 31 percent for Black patients. The other significant findings were that Black patients requiring an ICD appeared at younger ages, by five to ten years, and the risk of death for Black patients, despite having an ICD to protect them, is two times higher.
There are two types of heart failure. In one, a heart attack can leave a scar, which develops the potential for future heart failure. This is ischemic cardiomyopathy (ICM). In the other, heart failure is due to comorbidities, such as diabetes and hypertension. This is non-ischemic cardiomyopathy (NICM). An interesting note in the study shows there was virtually no difference in results for Black and white patients with ICM because the scar is essentially the same in both races, therefore they have the same issues and receive the same treatment. It’s only in patients with NICM that there are stark differences between Black and white patients.
These results beg the question: why? Principal investigator Ilan Goldenberg, MD, said they can hypothesize some reasons for the differences, but not fully draw solid conclusions. “It is possible that Black patients are not managed as well as white patients because of health care disparities, but we did not identify any significant differences in our study. We did identify that after one year, Black patients were more likely to discontinue some medications, but the reasons for that are unknown as well. The younger age of onset and the increased rate of comorbidities, such as diabetes and hypertension, among Black patients with NICM is striking and may contribute to the worse outcomes due to more advanced heart disease.”
The authors applied the Gini Index to their results. This index looks at zip codes across the country to compare its citizens wealth to areas surrounding it. For this particular study, the index scores for patients indicated that Black patients did tend to come from areas with lower socioeconomic status. “Future studies should examine closely social determinants of health, which were not captured in our clinical trials, to see why these findings occurred,” said Goldenberg.
Lead author Arwa Younis, MD, is a former research fellow from the URMC Clinical Cardiovascular Research Center who is now at the Cleveland Clinic and still holds an adjunct position with URMC. Younis knew going into the study that there were differences between racial groups with ICDs, but he was surprised by the extent of the results. “There’s nothing worse than getting a shock for a patient,” said Younis. “And it’s difficult to see a patient continue to receive shocks despite being on optimal medical therapy. In our study, we assessed patient compliance at the one-year mark and more than 85 percent of patients remained compliant. So, despite being on optimal medical therapy and having a high compliance rate, the burden of disease remained very high for Black patients.”
According to Younis, these results mean that Black patients with an ICD should receive aggressive positive treatment as early as possible. This means monitoring patients closely, referring to specialists as needed, and implanting devices earlier on. Goldenberg agrees: “We believe the main implication of this study is that because we now know that Black patients who have heart failure are more likely to have more advanced arrhythmias, they should be considered earlier for an ICD defibrillator to protect them from sudden cardiac death.” He also notes that primary prevention and treatment of comorbidities such as diabetes and hypertension may be one way to help prevent the burden of cardiac disease in Black patients.
Additional co-authors of the study from URMC include Sanah Ali, MD, Ido Goldenberg, MD, Scott McNitt, MS, Bronislava Polonsky, MS, Mehmet Aktas, MD, Valentina Kutyifa, MD, PhD, and Wojciech Zareba, MD, PhD. Co-authors from the Cleveland Clinic include Eileen Hsich, MD, and Oussama Wazni, MD, MBA.
METHOD OF RESEARCH
Meta-analysis
SUBJECT OF RESEARCH
People
ARTICLE TITLE
Arrhythmia and Survival Outcomes Among Black Patients and White Patients With a Primary Prevention Defibrillator
ARTICLE PUBLICATION DATE
18-Jul-2023
COI STATEMENT
Drs Younis, Ali, Ido Goldenberg, and Aktas, and S. McNitt and B. Polonsky, have nothing to declare. Drs Kutyifa, Wazni, Zareba, and Ilan Goldenberg report receiving grants from Boston Scientific.
