Researchers from Johns Hopkins University report that changes in the left atrium’s structure are linked to a 35% higher chance of dementia, even when heart function appears normal. Findings were published in the Journal of the American Heart Association.
The analysis drew on data from more than 15,000 participants enrolled in the Long-Term Atherosclerosis Risk at Communities study (ARIC), which began in 1987. Participants hailed from multiple states across the United States and attended clinics every three years. The current analysis compared data from 5,078 participants with a mean age of 75, using information collected during the fifth (2011–2013), sixth (2016–2017), and seventh (2018–2019) clinic visits.
Cognitive function was evaluated with neuropsychological tests and interviews conducted with some participants’ spouses or children. Cardiac health was assessed through an electrocardiogram, heart ultrasound, and blood tests to evaluate heart function overall and specifically the left atrium.
In the study, 763 participants developed dementia and 1,709 showed signs of atrial cardiopathy. Those with atrial cardiopathy faced a 35% higher risk of dementia. The risk remained elevated even without atrial fibrillation or stroke, at 28% and 31% respectively.
Atrial cardiomyopathy refers to structural changes in the left atrium that are linked to a greater likelihood of stroke and atrial fibrillation. These conditions, in turn, are associated with a higher risk of dementia. The researchers noted that even asymptomatic cardiomyopathy correlates with cognitive decline, underscoring the importance of regular cardiovascular screening for older adults.
Researchers also cautioned that some participants may have had undetected asymptomatic atrial fibrillation or prior silent strokes. As a result, the data should be interpreted as associative, not proof of a direct cause-and-effect relationship.
The study involved investigators from the University of Minnesota, the Mayo Clinic, the University of Mississippi, the Bloomberg School of Public Health, Harvard Medical School, and the National Institute of Neurological Disorders and Stroke.