An increased risk was observed even in those who had neither atrial fibrillation nor a stroke, both of which are known to be associated with dementia.

The latest study published today in the Journal of the American Heart Association found that structural or functional abnormalities in the heart’s left atrium, with or without symptoms, may increase a person’s risk of dementia by 35%. Even among people who had neither atrial fibrillation nor a stroke, which are known to be linked to dementia, the risk of dementia went up.

The left atrium is one of the four chambers of the heart. It gets blood from the lungs and sends it to the left ventricle. The left ventricle then sends the blood to the rest of the body. Atrial cardiopathy, an anomaly in the left atrium’s structure or function, is frequently used as a biomarker, or predictor, of a person’s risk for developing heart disease. Atrial cardiopathy is linked to a higher chance of having a stroke or atrial fibrillation, both of which are linked to a higher chance of getting dementia. The goal of the research team, which was led by Michelle C. Johansen, M.D., Ph.D., assistant professor of neurology at The Johns Hopkins University School of Medicine in Baltimore, was to establish whether there is a connection between atrial cardiopathy and dementia and, if so, whether it is distinct from atrial fibrillation and stroke.

The findings of the study underscore the need for further investigation into the connections and mechanisms between an atrial dysfunctional state that may be subclinical (not exhibiting symptoms) and the recently discovered association with dementia.

People who took part in this study were part of a larger group of more than 15,000 people who were originally recruited for the ongoing Atherosclerosis Risk in Communities (ARIC) study. This study, which started in 1987, is looking at the health of people’s hearts in four different U.S. communities. Participants in the ARIC study ranged in age from 45 to 65 and came from urban centers like Minneapolis and Jackson, Mississippi, as well as rural locations like Forsyth County, North Carolina, and Washington County, Maryland. All ARIC participants underwent clinical visits every three years, and the research and data that resulted, including hospital record abstraction, ECG tracings, doctor and coroner questionnaires, as well as death certificate data, have helped to uncover new information and establish best practices for treating atherosclerosis, heart disease, kidney disease, diabetes, stroke, and cognitive decline. The fifth ARIC clinical visit, between 2011 and 2013, was used as the baseline for this study, which also includes data and assessments from the participant’s sixth and seventh visits, between 2016 and 2019.

Of the 5,952 participants who came back for their fifth clinical appointment, 5,078 were included in the study; 59% of the participants were female and 41% were male. The sample of 5,078 people had an average age of 75 and self-identified as Black adults 21% of the time. The ARIC participants were assessed for cognitive decline indicative of dementia during their fifth, sixth, and seventh clinical visits.

In addition to an informant interview with a subgroup of participants, researchers assessed cognitive impairment in all participants using a thorough battery of neuropsychological tests from the Uniform Data Set of the Alzheimer’s Disease Centers program of the National Institute on Aging. Informant interviews are screening tests that ask a spouse, adult child, or close friend of the adult being examined for cognitive decline a series of questions, such as the Eight-Item Informant Interview to Differentiate Between Aging and Dementia. The neuropsychological test battery is made up of short tests of processing speed, episodic memory, language, attention, and executive function. A computer diagnostic algorithm developed a dementia diagnosis based on the findings of testing, which was then confirmed by an expert using the Diagnostic and Statistical Manual of Mental Disorders and the criteria given by the National Institutes of Health and the National Institutes of Health.

To evaluate the cognitive status of the participants, hospital discharge codes—obtained as part of the ARIC study either directly from hospital discharge indices or from an indexing service—and death certificate data—obtained as part of the ARIC study from the Automated Classification of Medical Entities system—were also included. In order to evaluate the size and functionality of the left atrium of the heart and look for indications of atrial cardiopathy, a cardiac examination that included echocardiography, electrocardiography (EKG/ECG), and blood work was also carried out.

In the course of the more than 30 years of follow-up, 763 people got dementia, while 1,709 were diagnosed with atrial cardiopathy, according to the study of the collective health data. Dementia found to be 35% more likely to develop in those with atrial cardiopathy. Even after taking into account other vascular factors and accounting for those who had atrial fibrillation and stroke, the researchers still found a 31% and 28% increase in dementia risk in patients with atrial cardiopathy. The researchers hypothesized that atrial fibrillation or stroke alone do not cause an atrial cardiopathy condition that results in dementia.

Even though the researchers say that the results don’t prove a cause-and-effect relationship, they stress how important it is to lower the risk of heart and blood vessel diseases. The likelihood that some study participants’ silent strokes or asymptomatic atrial fibrillation may have gone unnoticed was one of the study’s limitations. Additionally, because dementia develops gradually, some research participants with lesser symptoms might have been overlooked, and other patients might have passed away before dementia was seen and recorded. The four communities that makeup ARIC in Forsyth County, North Carolina, Washington County, Maryland, Minneapolis, and Jackson, Mississippi may not represent generalizable populations for the study.

Image Credit: Getty

You were reading: People With This Condition Appears To Be 35% More Likely To Develop Dementia