Structural or functional abnormalities within the heart’s left atrium, with or without symptoms, may increase a person’s risk of developing dementia later in life by 35 percent, according to new research published in the Journal of the American Heart Association.
Dementia risk increased even among those who did not experience atrial fibrillation or stroke, two conditions known to be associated with dementia.
The left atrium is one of four chambers of the heart and is responsible for receiving blood from the lungs and pumping it into the left ventricle, which then pumps the blood to the rest of the body.
An abnormality in the structure or functioning of the left atrium, known as atrial cardiopathy, can often serve as a biomarker, or predictor, of a person’s cardiac risk. Atrial cardiopathy is associated with an increased risk of stroke and atrial fibrillation, which are both linked to an enhanced risk of dementia.
In a study led by Mr. Michelle C. Johansen, M.D., Ph.D., an assistant professor of neurology at The Johns Hopkins University School of Medicine in Baltimore, the research team aimed to determine the relationship between atrial cardiopathy and dementia, and if so, whether it is independent of atrial fibrillation and stroke.
The study results highlight the need to get a better understanding of the relationship and mechanisms between a state of atrial dysfunction, that may be subclinical and the newly uncovered association with dementia, the researchers noted.
The current analysis included 5,078 of the 5,952 participants who returned for their fifth clinical visit, 59 percent were female, and 41 percent were male. The group of 5,078 were an average age of 75 years old, and 21 percent self-identified as Black adults. During their fifth, sixth and seventh clinical visit, the ARIC participants were evaluated for cognitive decline indicating dementia.
Researchers evaluated cognitive decline in all participants with a comprehensive neuropsychological test battery from the Uniform Data Set of the Alzheimer’s Disease Centers program of the National Institute on Aging, as well as an informant interview in a subset of participants.
The analysis of the collective health data found that throughout the more than 30 years of follow-up, 763 people developed dementia, and 1,709 had atrial cardiopathy. When the researchers adjusted for participants who experienced atrial fibrillation and stroke, even after accounting for other vascular risks, they still observed a respective 31 percent and 28 percent increase in dementia risk in patients with atrial cardiopathy.