Abnormal Upper Heart Chamber May Boost Dementia Risk

WEDNESDAY, Aug. 10, 2022 (HealthDay News) -- If the left upper chamber of your heart doesn't work properly, do your chances of dementia climb?

Yes, suggests new research that found it may raise the risk by 35%, even in people who have never had a stroke or atrial fibrillation.

The left atrium, one of the heart's four chambers, transfers blood from the lungs to the left ventricle (lower left chamber), which distributes the blood to the rest of the body. Atrial cardiopathy, an abnormality in the left atrium's structure or function, is frequently a predictor for heart disease risk. Atrial fibrillation and stroke are both linked to an increased risk of dementia, and atrial cardiopathy is associated with the development of both atrial fibrillation and stroke.

In the study led by Dr. Michelle Johansen, an assistant professor of neurology at Johns Hopkins University School of Medicine in Baltimore, researchers tried to determine whether there is a connection between atrial cardiopathy and dementia and, if so, whether it is distinct from atrial fibrillation and stroke.

Data was taken from the Atherosclerosis Risk in Communities study, which began in 1987, an ongoing investigation into heart health among people residing in four diverse U.S. communities: Minneapolis, Jackson, Miss., Forsyth County, N.C., and Washington County, Md. More than 15,000 participants were originally enrolled and ranged in age from 45 to 65.

All participants underwent clinical visits every three years, and this particular study tracked the participants through their sixth visit, between 2016 and 2017, and their seventh visit, between 2018 and 2019.

Of the 5,952 participants who came back for their fifth clinical visit, 5,078 were included in the analysis; 59% of the participants were female and 41% were male. All had their cognitive function assessed for dementia at their fifth, sixth and seventh clinical visits.

Brief assessments of processing speed, episodic memory, language, attention and executive function were included in the battery of neuropsychological tests. An expert determined a diagnosis of dementia using criteria established by the U.S. National Institutes of Health.

To evaluate the size and functionality of the left atrium of the heart, a cardiac evaluation included echocardiography, electrocardiography (EKG/ECG) and blood work.

Over more than 30 years of follow-up, 763 people developed dementia and 1,709 were diagnosed with atrial cardiopathy. Dementia appeared to be 35% more likely to develop in those with atrial cardiopathy.

Even after taking into account other vascular risks and accounting for participants who had atrial fibrillation and stroke, the researchers still found a 31% and 28% increase in dementia risk, respectively, in patients with atrial cardiopathy.

While acknowledging that the results do not confirm a direct cause-and-effect relationship, the researchers stress the significance of reducing the risk of heart disease.

The findings were published Aug. 10 in the Journal of the American Heart Association.

Dementia progresses gradually, so some study participants may have had milder symptoms that were overlooked, and some patients may have passed away before dementia was identified and recorded, the scientists noted in a journal news release.

More information

Visit the U.S. National Institutes of Health for more on heart disease and dementia.

SOURCE: Journal of the American Heart Association, news release, Aug. 10, 2022