When the results from a landmark heart health study of American Indians were published in 1999, they shattered the health care community’s erroneous assumption that this population rarely got heart disease—that somehow they were naturally protected from it. Indeed, the study highlighted the exceedingly high rate of heart disease and its risk factors among American Indians compared to the general U.S. population, and it marked a trend that has held for years. Today, despite being just two percent of the population, American Indians account for 18 percent of heart disease-related deaths.
Now, however, recent findings from that same study—the NHLBI-funded Strong Heart Study, the largest and longest investigation of heart disease among American Indians—is bearing some good news. The results showed that during one 25-year span, new cases of heart disease among the study’s participants dropped.
“Heart disease is the number one killer in this community, and any downward trend in new cases is heartening,” said Barbara Howard, Ph.D., a principal investigator for the SHS and co-author on the latest study who also is the former president of the MedStar Health Research Institute in Hyattsville, Maryland. “It gives all of us who care about the health of this population an opening to explore which preventive strategies would be most effective.”
The Strong Heart Study began in 1988 and had more than 7,600 participants representing 12 communities in the Southwest and the Northern and Southern Plains. The Strong Heart Family Study recruited 3,800 participants from the Strong Heart Study and their multi-generational relatives between 2000 and 2003. All participants received information about cardiovascular disease and its risk factors. During the baseline and follow-up exams, participants were referred for medical treatment if they presented with risk factors or conditions such as high cholesterol or blood pressure, diabetes, or heart disease. Most of the participants from both cohorts are still followed for cardiovascular disease morbidity and mortality. The most recent findings, published last October, came from an analysis of Strong Heart Study and Strong Heart Family Study data from 5,627 of the participants and included all men and women who were between age 30 and 85 between enrollment and December 31, 2013.
Researchers divided participants born within a decade of each other into groups. They compared the rates of new cases of cardiovascular disease for specific age categories over time and found that risks had generally declined over a generation. For example, American Indian men between 75-79 years old who were born between 1915-1924 had a 31% risk of developing heart disease in the next five years, whereas men born between 1934-1944 had just a 20% risk when they were 75-59 years old. Heart disease risk also declined in women aged 75-79, from 21% to 10% for those born in 1915-1924 and 1934-1944, respectively. The study found that the risk of dying from heart disease declined for American Indian men, but it was not clear whether women also experienced lower heart disease death rates.
Howard said several factors could be responsible for the downturns. “Improvements in healthcare access, quality of care, medication adherence, or positive lifestyle changes, could all be playing a role,” she said. “Additional influences could include aggressive therapy for people with cardiovascular disease risk, new treatment options, or changes in healthcare guidelines that affect everyone, regardless of age—such as those related to smoking and alcohol.” The research team’s next steps include a study to determine long-term changes in heart disease risk factors, such as high cholesterol or blood pressure and elevated blood sugar levels, in the community.
The study, Howard said, highlights the importance of raising even greater awareness in the American Indian community about medical conditions and lifestyle habits that can lead to heart disease. Better access to care and information on prevention could also help guide the public health response to yet another health crisis in this community—the disproportionately high death toll from coronavirus disease 2019 (COVID-19), for which heart disease is a primary risk factor. And with cases of COVID-19 spiking higher than ever, some public health efforts are doing just that. One new NIH effort, called the Community Engagement Alliance Against COVID-19 Disparities, or CEAL, is trying to ensure that accurate information about COVID-19, including its complex links to heart disease, reaches hard hit communities.
Among health professionals, concerns abound. While having heart disease can increase the risk of having complications of COVID-19, emerging data shows that the disease, which is caused by the virus SARS-CoV-2, can lead to heart damage secondary to lung failure and a lack of enough oxygen in the tissues to sustain bodily functions. Another concern: people with heart disease who do not have COVID-19 but are afraid to seek care for their heart problems out of fear of being exposed to the virus.
CEAL leaders say they want to help minimize fears like this. They are focusing on 11 states with ethnic and racial minority communities that are especially burdened by COVID-19. According to the Centers for Disease Control and Prevention, American Indians, along with African Americans and Hispanics/Latinos, are experiencing the highest rates of illness, hospitalization and death from COVID-19. Arizona is amongst the hardest hit states, with American Indian/Alaska Native persons accounting for at least one third of all COVID-19 cases.
Sairam Parthasarathy, M.D., chief of the Division of Pulmonary, Allergy, and Critical Care and Sleep Medicine and member of the BIO5 Institute at the University of Arizona College of Medicine, is leading that state’s CEAL program. Currently, he said, the CEAL team is tapping into existing community relationships, and they’re using those partners to help disseminate accurate information.
“Once we address the misinformation and mistrust around COVID-19, we can disseminate information based on what we already know and look forward to creating COVID-19 follow-up clinics to better study and understand the long-term effects of the disease in these minority populations,” he said. “The messaging that we create most certainly could help people who had COVID-19 seek cardiac and comprehensive medical care.”