Aug. 22, 2022 – Older adults with an upper heart chamber that’s of abnormal size or doesn’t work well may have up to a 35% higher risk for dementia, according to new research.
The condition, called atrial cardiopathy, involves abnormalities in the left atrium, one of the two upper chambers of the heart. The link to dementia is present even if a person has not had heart symptoms, the study authors say.
The research, led by Michelle C. Johansen, MD, of the Department of Neurology at the Johns Hopkins University School of Medicine in Baltimore, was published online Aug. 10 in the Journal of the American Heart Association.
Atrial cardiopathy has been linked to a higher risk of stroke and atrial fibrillation (AFib), and because both stroke and AFib are linked to a higher dementia risk, it was important to investigate whether atrial cardiopathy is linked to dementia, the study authors said.
Then, the next question was whether that link is independent of AFib and stroke, and their research suggests that it is.
More Than 5,000 Adults Studied
For the study, the researchers looked at a diverse population of 5,078 older adults living in four U.S. communities: Washington County, MD; Forsyth County, NC; northwestern suburbs of Minneapolis; and Jackson, MS.
Just more than a third (34%) had atrial cardiopathy (average age 75 years, 59% female, 21% Black adults) and 763 of the people studied developed dementia.
Investigators found that atrial cardiopathy had a big link to dementia; people with the heart condition were 35% more likely to have dementia.
But the researchers noted that their findings show an association; in other words, this doesn’t necessarily mean this is evidence that the abnormal heart chamber is the cause of the dementia.
Clifford Kavinsky, MD, head of the Comprehensive Stroke and Cardiology Clinic at Rush University Medical Center in Chicago, says more research would need to be done to show convincing evidence that atrial cardiopathy causes dementia.
He calls the findings “provocative in trying to understand in a general sense how cardiac dysfunction leads to dementia.
“We all know heart failure leads to dementia, but now we see there may be a relationship with just dysfunction of the upper chambers,” he says.
Unresolved Questions
But still not clear is what is behind the connection, who is at risk, and how the increased risk can be prevented, he says.
Kavinsky also wonders whether the results eliminated all patients with atrial fibrillation, which is already known to be linked to dementia, a point the authors acknowledge as well.
Researchers list in the limitations that “asymptomatic AF or silent cerebral infarction may have been missed” in the process of recruiting people for the study.
Preventing heart disease is important for a wide variety of reasons, Kavinsky notes, and one of the reasons is heart disease’s connection to a decline in mental skills.
He says this study helps show that “even dysfunction of the upper chambers of the heart contributes to the evolution of dementia.”
The study underlines the need to shift to prevention with heart disease in general, and more specifically in atrial dysfunction, Kavinsky says, noting much of this dysfunction is brought about by high blood pressure or heart disease.