Atrial fibrillation (AF) is characterized by an irregular and frequently rapid heart rate. It has been linked to a number of cardiovascular complications, including stroke and heart failure. Recent studies have suggested a link between AF and an increased risk of dementia.
According to new research, people who have recently been diagnosed with atrial fibrillation (AF), the most common irregular heart rhythm, have a slightly higher risk of developing dementia than those who do not have the condition.
Nearly 197,000 patient records from Kaiser Permanente health systems in California were used in the study. Half of the patients had recently been diagnosed with atrial fibrillation; their control group counterparts were chosen for similar age and health profiles but did not have AF. The medical records of both patient groups were reviewed for an average of three years to identify subsequent dementia diagnoses, including Alzheimer’s disease. People with newly diagnosed atrial fibrillation were 13% more likely to develop dementia.
According to new research, people who have recently been diagnosed with atrial fibrillation (AF), the most common irregular heart rhythm, have a slightly higher risk of developing dementia than those who do not have the condition.
We know that atrial fibrillation is one of the strongest risk factors for ischemic stroke, but whether it increases the risk of developing dementia independently of having a stroke has been unclear. If it does, it will have significant clinical and public health implications, as atrial fibrillation is becoming more common both nationally and internationally.
Dr. Alan S. Go
“Previous studies that have examined the link between atrial fibrillation and dementia have yielded conflicting results, and we hope that our study’s large sample size helps to establish confidence in our findings,” said Dr. Nisha Bansal, a professor of medicine at the University of Washington School of Medicine. “The study also included a community-based, diverse population, which may increase the generalizability of our findings.”
Bansal was the paper’s corresponding author, and it was published in the Journal of the American Heart Association. Atrial fibrillation, a very rapid heart rhythm, can cause blood clots in the heart, increasing the risk of stroke and heart failure and shortening someone’s lifespan.
“We know that atrial fibrillation is one of the strongest risk factors for ischemic stroke, but whether it increases the risk of developing dementia independently of having a stroke has been unclear,” said senior author Dr. Alan S. Go, a senior research scientist at the Kaiser Permanente Division of Research. “If it does, it will have significant clinical and public health implications, as atrial fibrillation is becoming more common both nationally and internationally.”
The study covered nearly 197,000 patient records from Kaiser Permanente health systems in California from 2010 to 2017. Half of the patients had recently been diagnosed with atrial fibrillation; their control group counterparts were chosen for similar age and health profiles but did not have AF. The medical records of both patient groups were reviewed for an average of three years to identify subsequent dementia diagnoses, including Alzheimer’s disease.
People with newly diagnosed atrial fibrillation were 13% more likely to develop dementia. This risk appeared to be increased in people whose AF diagnosis occurred before the age of 65 (65% higher risk) and in people who did not have chronic kidney disease (20% higher risk).
The researchers used a methodology to mitigate the influence of other medical conditions also known to heighten dementia risk, Bansal said. So it was a surprise, she added, to find greater risk among relatively younger patients and those without kidney disease. As a nephrologist, Bansal is particularly interested in the influence of kidney disease on total body health.
“You don’t think about ostensibly healthier people being at a higher risk for serious health conditions – especially for a disease like dementia,” Bansal said. The findings also show that risks of complications related to atrial fibrillation are not uniform in all patients, she said.
“While many people with atrial fibrillation do not develop dementia, I believe this is a conversation that a patient with newly diagnosed atrial fibrillation should have with their doctor, weighing their potential individual risk of developing dementia as well as the risks and benefits of treating the atrial fibrillation.”
The next stages of this research, according to Bansal, will aim to better understand the biological mechanisms linking atrial fibrillation and dementia, as well as to investigate whether different AF therapies, such as catheter ablation of the heart muscle versus medication, affect patients’ trajectories for dementia and other complications.
