In this exploratory analysis of a US community-based cohort, several echocardiographic measures of lower left atrial function were significantly associated with an increased risk of subsequent dementia.
"To the best of our knowledge this is the first study that has looked at the link between echocardiogram-defined left atrial function and dementia," lead author Wendy Wang, MPH, University of Minnesota, Minneapolis, told theheart.org | Medscape Cardiology. "Our results suggest that atrial myopathy could signal an increased risk of developing dementia and treating this condition could be a potentially new approach to preventing dementia."
Their results "improve our understanding of the relationship between the heart and dementia, and strengthens the link between cardiac dysfunction and dementia," she said.
Senior author, Lin Yee Chen, MD, professor of medicine at the University of Minnesota Medical School, Minneapolis, added, "This study is important in highlighting the role of atrial myopathy as an independent risk factor for dementia."
But Wang noted that these findings should be regarded as preliminary and need to be confirmed in further studies. The study was published online in JAMA on March 22.
The researchers note that atrial myopathy — characterized by alterations in left atrial function and size — is associated with adverse cardiovascular events. Because lower left atrial reservoir function has been associated with presence of silent brain infarcts and white matter hyperintensities, it is possible that atrial myopathy is also associated with dementia.
Prior research has found electrocardiographic (ECG) markers of atrial myopathy to be associated with greater cognitive decline and dementia. But whether abnormal left atrial function and size, as assessed by echocardiography, are linked to increased dementia risk is unknown.
The current study was conducted to assess the association of echocardiographic measures of left atrial function and size with incident dementia in the Atherosclerosis Risk in Communities (ARIC) study, a large community-based cohort.
For the study, various measures of left atrial function and size were evaluated on the 2-dimensional echocardiograms taken as part of the ARIC study in 2011-2013. The measures were quantified by speckle tracking and volumetric analysis. Subsequent dementia cases over a median 6-year follow-up were identified using in-person and phone cognitive assessments, hospitalization codes, and death certificates, also as part of the ARIC study.
The study involved 4096 participants (mean age, 75 years; 60% women; 22% Black individuals), and 531 dementia cases were ascertained over the follow-up period.