A new study published in the November 2019 journal Circulation found that American Indians could be at a greater risk than all other races for developing atrial fibrillation.
Atrial fibrillation is an irregular heartbeat that can increase the risk of a host of serious health problems, including stroke and heart failure — and it’s incredibly common, with between 2.7 million and 6.9 million Americans living with the condition, according to the Centers for Disease Control and Prevention.
For the study, Gregory Marcus, MD, a professor of medicine at the University of California in San Francisco, and colleagues analyzed a dataset of more than 16 million Californians who went to the hospital at least twice between 2005 and 2011. Of those hospitalizations, researchers found that the overall incidence of afib was higher in American Indians. Results showed 7.5 new cases per year for every 1,000 American Indians compared with 6.9 new afib cases for every 1,000 patients who were white, Black, Hispanic, or Asian.
The difference persisted after controlling for factors like age, sex, income, and other heart conditions.
The findings were a surprise to the team, especially Dr. Marcus, whose previous research found that whites had higher rates of new atrial fibrillation diagnoses compared with Blacks, Hispanics, and Asians.
"Understanding the mechanisms and factors by which American Indians experience this higher risk may help investigators better understand the fundamental causes of atrial fibrillation that prove useful to everyone at risk for afib, regardless of their race or ethnicity," Marcus said in a press release from October 21, 2019.
Marcus said that since self-reported Hispanic people have been found to be at a reduced risk of atrial fibrillation, and many Hispanic people have indigenous ancestry from North and South America, the team assumed American Indians would similarly have lower rates of the condition.
But he offered two explanations for the data: “One is that there is some genetic predisposition among American Indians that is more potent than the assumed predisposition of European ancestry, and the other is there is a behavior or exposure that explains the difference.”
Prevention Is Key to Risk Reduction Regardless of Race
“Unlike other diseases in cardiology, the presence of atrial fibrillation is actually rising,” says Marcus. “The causes remain somewhat mysterious — we don’t completely understand why some people get atrial fibrillation and others do not.”
Marcus said that since atrial fibrillation is often found in patients with other health problems, there’s a growing awareness that improving overall health can contribute to positive effects on patient outcomes. And catching and treating atrial fibrillation can prevent many of the more serious problems from developing.
There are a host of known risk factors, including:
- Advancing age
- Being male
- High blood pressure
- Heart failure
- Sleep apnea
- Smoking and alcohol use
But patients must have access to good healthcare to spot and treat the condition and to help improve patients’ overall health.
“It could be that the healthcare provided to the American Indian population is suboptimal and their access to healthcare resources is reduced,” Marcus said. “This [study outcome] could be a marker of insufficient healthcare access or provider resources.”