Atrial cardiomyopathy linked to dementia in later life: Neuroscience today

Article in brief

A new study has found an association between dementia and atrial cardiopathy. Independent experts recommend that neurologists examine and promote heart and brain health.

Older adults with atrial cardiomyopathy may be more likely to develop dementia, according to findings published in the August 16 issue of Journal of the American Heart Association.

“There is mounting evidence that the way we think about dementia is a little more complex than we originally thought, and that vascular contributions to cognitive impairment are very important,” said lead study author Michelle Johansen. Neuroscience at the Johns Hopkins University School of Medicine and faculty at the Johns Hopkins Bloomberg School of Public Health.

Dr. Johansen noted that atrial fibrillation has been associated with dementia in previous research, but that atrial fibrillation has not been associated with dementia before. “Recognizing that vascular risk plays an important role in cognitive decline, and that we have to do a better job than we are currently trying to prevent the onset of cognitive decline, we decided to do this study,” she said.

Study details

Dr. Johansen and colleagues at Johns Hopkins prospectively screened 5,078 older adults as part of the Atherosclerosis Risk in Communities (ARIC) Study who live in four US communities: Washington County, Maryland; Forsyth County, North Carolina; Northwest Suburbs of Minneapolis, MN; and Jackson, Ms. The participants did not have dementia when they were recruited into the study in the late 1980s. Specifically, the researchers collected data between 2011 and 2019 at three separate visits to determine whether or not participants had atrial cardiomyopathy, and dementia in the latter two.

“This study indicates that in addition to atrial fibrillation, atrial cardiomyopathy, which is more common than atrial fibrillation and is itself a risk factor for atrial fibrillation, is also a risk factor for dementia even in people without known stroke or atrial fibrillation. .” – DR. Julie A Schneider

The mean age of the sample was 75 years, 59 percent were women, and 21 percent were black. About a third (34 percent) had atrial cardiomyopathy, and 763 of the total sample developed dementia during the 6.12-year follow-up period.

Atrial cardiopathy was associated with a higher risk of dementia (adjusted heart rate = 1.35; 95 percent CI, 1.16-1.58), and the association was stronger when participants met at least two criteria for atrial cardiopathy (adjusted heart rate = 1.54; 95 percent CI). cent CI, 1.25 – 1.89).

The researchers excluded people with atrial fibrillation and the association remained; (adjusted heart rate = 1.31; 95% CI, 1.12 – 1.55), and the same was true when participants with stroke were excluded (adjusted heart rate = 1.28; 95% confidence interval, 1.09 – 1.52), as Researchers wrote. The researchers found that atrial fibrillation mediated 4 percent of the effect of atrial cardiopathy on dementia (s= .005) Stroke mediated 9 percent of the effect (s= .048).

Dr. Johansen noted that increased inflammation is linked to both atrial dysfunction and dementia, but said no study has strong answers about how atrial cardiopathy can lead to later dementia.

“Could it be because the left atrium is unhealthy, blood collects there, and as a result, not enough blood gets to the brain? Or do you have microembolism that does not cause a stroke, but may contribute to a stroke?” she said: “That’s what we’re trying to find out, and it’s probably a combination of factors.”

Dr. Johansen said she will continue to follow the participants in the ARIC study, and for now, she’s giving this advice: “If you’re a middle-aged adult with 20 pounds to lose, and you keep delaying your gym membership, and your ex-grandmother with diabetes passed away from a disease Alzheimer’s, this is a wake-up call to start taking care of yourself.”

The relationship of the heart to the brain

Judy Edwards, PhD, associate professor in the University of Ottawa’s School of Epidemiology and Public Health and director of the Department of Brain and Heart Nexus Research Program at the University of Ottawa Heart Institute.

Edwards notes that the findings have important implications for neurologists, because although anticoagulant therapy has been shown to reduce the risk of cognitive impairment and dementia, current risk assessment and treatment decision tools are based primarily on the onset of apparent atrial fibrillation either before or at stroke time. “However, what these data show us is that cardiac changes that frequently occur prior to the onset of atrial fibrillation may be useful in identifying people at high risk of cognitive decline,” she said.

Figure 2

“There is mounting evidence that the way we think about dementia is a little more complex than we originally thought, and that vascular contributions to cognitive impairment are very important.” – Dr. Michelle Johansen

Based on the findings, Dr. Edwards acknowledged that neurologists should consider atrial cardiopathy and comorbid heart disease when assessing cognitive risk, and that individuals with signs of left atrial cardiopathy may be an important group to target for screening or potential anticoagulation if it persists. randomly or clinically. Trials demonstrate benefit in that population.

She added that health care providers may also have to educate their patients about the relationship between heart health and brain health and how reducing vascular risk can benefit their heart and cognitive health.

The heart isn’t the only organ that contributes to cognitive function, according to Costantino Idikola, MD, professor of neurology Ann Barrish Tetzel and director and chair of the Feil Family Brain and Mind Research Institute at Weill Cornell Medicine.

“The landscape of cognitive impairment is rapidly becoming diverse and polymorphic. There is increasing evidence that peripheral organs contribute significantly to the risk of dementia, not only in the heart, but also in the kidneys, and as recently explained by Dr. Neil Barrick here at Weill Cornell, which is also liver disease subclinical”.

He added that efforts to reduce dementia risk have begun to include the contribution of factors outside the brain “that may exacerbate neurovascular and neurodegenerative diseases, and the heart is a prominent target.”

Dr. Iyadkula said cardiologists and family physicians who treat patients with vascular risk factors can use medications to maintain a healthy heart and vascular system to control high blood pressure, diabetes and hyperlipidemia, for example, as well as encourage patients to adopt lifestyle changes. . Reducing risky behaviours, such as smoking, a sedentary lifestyle, and excessive alcohol intake, for example.

Julie A. Schneider, MD, Deborah R and Edgar De Janota, MD, presidential professor of pathology and neurosciences and director of the Alzheimer’s Research Center at Rush University Medical Center agreed.

“Although there isn’t enough information yet to recommend dementia prevention strategies in people with atrial cardiomyopathy, it is important for patients to know that things that are good for your heart are also good for your brain. For example, a healthy diet, physical activity, moderation in blood pressure, and sugar. the blood “.

She noted the strong link between heart health and brain health. As noted in this manuscript, stroke is a known risk factor for dementia and atrial fibrillation, a common heart condition in the elderly, and a known risk factor for stroke. This study indicates that in addition to atrial fibrillation, atrial cardiomyopathy, which is more common than atrial fibrillation and is itself a risk factor for atrial fibrillation, is also a risk factor for dementia even in people without a known stroke or atrial fibrillation. .

There is a clear, long-term recognition that heart disease affects the brain through impaired perfusion, said Sudha Seshadri, MD, FAAN, director of the Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases at UT Health San Antonio and principal investigator on the Framingham Heart Study at Boston University. Brain due to heart failure, with overt and subtle ischemia manifesting as strokes, transient ischemic attack, or white matter hyperintensity in individuals with atrial fibrillation because vascular risk factors such as hypertension and diabetes can affect the large arteries of the heart and brain. Thus, we have shown that coronary calcium is a risk factor for stroke. Impairment of the blood-brain barrier and dysfunction can lead to increased deposition of amyloid.”

Dr. Al-Sashadri stressed the importance of the examination. “I think neurologists might get an electrocardiogram at a low cost (as part of a routine for subjective or mild cognitive impairment,” said Dr. Seshadri.) Additionally, directing our neurologists toward considering subclinical disease testing in other organ systems is A step in the right direction.”

The ARIC study is funded by the National Heart, Lung, and Blood Institute, the National Institute of Neurological Disorders and Stroke, the National Institute on Aging, and the National Institute on Deafness and Other Communication Disorders.

Disclosures

Dr. Johansen has no disclosures. Dr. Schneider reportedReceive consultant fees forAlnylum Pharmaceuticals and CerveauTechnologies.