Structural or functional abnormalities inside the heart’s left atrium, with or without symptoms, may increase an individual’s risk of developing dementia later in life by 35%, in response to recent research published today within the Journal of the American Heart Association, an open access, peer-reviewed journal of the American Heart Association. Dementia risk increased even amongst those that didn’t experience atrial fibrillation or stroke, two conditions known to be related to dementia.

The left atrium is one among 4 chambers of the center and is liable for receiving blood from the lungs and pumping it into the left ventricle, which then pumps the blood to the remaining of the body. An abnormality within the structure or functioning of the left atrium, generally known as atrial cardiopathy, can often function a biomarker, or predictor, of an individual’s cardiac risk. Atrial cardiopathy is related to an increased risk of stroke and atrial fibrillation, that are each linked to an enhanced risk of dementia. In a study led by 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 find out the connection between atrial cardiopathy and dementia, and if that’s the case, whether it’s independent of atrial fibrillation and stroke.

The study results highlight the necessity to get a greater understanding of the connection and mechanisms between a state of atrial dysfunction, that could be subclinical (not presenting symptoms) and the newly uncovered association with dementia, the researchers noted.

Participants in the present evaluation were part of a bigger study group of greater than 15,000 people originally recruited for the continuing Atherosclerosis Risk in Communities (ARIC) study, which began in 1987 to research heart health in people living inside 4 diverse communities throughout the U.S. ARIC study participants were ages 45–65 years in the beginning of the study and from rural areas within the U.S. (Forsyth County, North Carolina, and Washington County, Maryland) and concrete areas: Minneapolis and Jackson, Mississippi. All ARIC participants attended clinical visits every three years, and the resulting research and data – including hospital record abstraction, ECG tracings, and physician and coroner questionnaires, in addition to death certificate data – have led to discoveries and guidelines surrounding atherosclerosis, heart disease, kidney disease, diabetes, stroke and cognitive decline. This evaluation uses data and assessments gathered during participants’ fifth ARIC clinical visit, between 2011 and 2013 as a baseline, and follows the participants through their sixth visit, between 2016 and 2017, and their seventh visit, between 2018 and 2019.

The present evaluation included 5,078 of the 5,952 participants who returned for his or her fifth clinical visit; 59% were female, and 41% were male. The group of 5,078 were a mean age of 75 years old, and 21% 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 an informant interview in a subset of participants. Informant interviews are a screening test of questions, equivalent to the Eight-Item Informant Interview to Differentiate Between Aging and Dementia, given to a spouse, adult child or close friend of the adult being evaluated for cognitive decline. The neuropsychological test battery consists of transient measures of processing speed, episodic memory, language, attention and executive function. A diagnosis of dementia was generated based on testing results by a pc diagnostic algorithm after which decided upon by an authority based on the Diagnostic and Statistical Manual of Mental Disorders and the standards outlined by the National Institutes of Health and the National Institutes of Health.

Hospital discharge codes – obtained as a part of the ARIC study either directly from hospital discharge indices or from an indexing service or from an indexing service – and death certificate data, obtained as a part of the ARIC study from the Automated Classification of Medical Entities system, were also included to evaluate participants’ cognitive status. Moreover, cardiac evaluation, including echocardiography, electrocardiography (EKG/ECG) and blood work, was conducted to evaluate the dimensions and performance of the left atrium of the center to envision for signs of atrial cardiopathy.

The evaluation of the collective health data found that throughout the greater than 30 years of follow-up, 763 people developed dementia, and 1,709 had atrial cardiopathy. The participants with atrial cardiopathy seemed to be 35% more prone to develop dementia. 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% and 28% increase in dementia risk in patients with atrial cardiopathy. The researchers suggested that a state of atrial cardiopathy resulting in dementia s just isn’t a results of atrial fibrillation or stroke alone.

While the researchers note the outcomes don’t imply causality, they emphasize the importance of lowering vascular and heart disease risks. Among the many study’s limitations was the likelihood that asymptomatic atrial fibrillation or silent strokes can have been missed in some study participants. Moreover, dementia develops slowly, subsequently, some participants with milder symptoms can have been missed, and a few patients within the study can have died before dementia was observed and documented. The study can also not be generalizable amongst populations with different demographics than the 4 communities in Forsyth County, North Carolina; Washington County, Maryland; Minneapolis; and Jackson, Mississippi that comprise ARIC.

Source:

American Heart Association

Journal reference:

Johansen, M.C., et al. (2022) Risk of Dementia Associated With Atrial Cardiopathy: The ARIC Study. Journal of the American Heart Association. doi.org/10.1161/JAHA.121.025646.