Researchers say atrial fibrillation can cause a decline in memory skills, but taking blood thinners may help.

Share on Pinterest
Atrial fibrillation is when the heart’s normal rhythm is out of sync. Getty Images

A new study on the link between atrial fibrillation and dementia illustrates the complex relationship between strong drugs that come with serious potential side effects and the chance for improvement they offer an ailing patient.

People with a kind of irregular heartbeat known as atrial fibrillation may experience a quicker decline in thinking and memory skills and have a greater risk of dementia than those without the ailment, according to the study published earlier this month in the online issue of Neurology, the medical journal of the American Academy of Neurology.

People who took drugs to keep their blood from clotting were actually less likely to develop dementia than those who did not take blood thinners.

Atrial fibrillation is a form of arrhythmia, in which the heart’s normal rhythm is out of sync.

As a result, blood may pool in the heart, possibly forming clots that may go to the brain, causing a stroke.

It seems taking a medication to thin the blood may not only resolve some of those clots but can also reduce that patient’s risk of developing dementia.

“Compromised blood flow caused by atrial fibrillation may affect the brain in a number of ways,” said Chengxuan Qiu, PhD, a study author from the Karolinska Institutet and Stockholm University in Sweden. “We know as people age, the chance of developing atrial fibrillation increases, as does the chance of developing dementia. Our research showed a clear link between the two and found that taking blood thinners may actually decrease the risk of dementia.”

The research was a population-based cohort study involving 2,685 people with no dementia.

Study participants came from the Swedish National Study on Aging and Care in Kungsholmen, who were regularly examined from 2001–2004 to 2010–2013.

Atrial fibrillation was ascertained from clinical examination, ECG, and patient registry.

Global cognitive function was assessed using the Mini-Mental State Examination.

Data were analyzed using multiple linear mixed-effects and Cox regression models.

Researchers said that those who had atrial fibrillation had a faster rate of decline in thinking and memory skills than those without the condition and were 40 percent more likely to develop dementia.

Of the 2,163 people who did not have irregular heartbeat, 278 developed dementia, or nearly 13 percent. Of the 522 people with irregular heartbeat, 121 developed dementia, or 23 percent.

Another finding was that people who took blood thinners for atrial fibrillation had a 60 percent decreased risk of dementia.

Of the 342 people who did not take blood thinners for the condition, 76 people developed dementia, or 22 percent.

Of the 128 people taking blood thinners, 14 developed dementia, or 11 percent.

There was no decreased risk among people who took an antiplatelet treatment such as aspirin.

Over the course of the study, an additional 279 people, or 11 percent, developed atrial fibrillation, and 399, or 15 percent, developed dementia.

“Assuming that there was a cause-and-effect relationship between using blood thinners and the reduced risk of dementia, we estimated that about 54 percent of the dementia cases would have been hypothetically prevented if all of the people with atrial fibrillation had been taking blood thinners,” Qiu said.

“Additional efforts should be made to increase the use of blood thinners among older people with atrial fibrillation,” Qiu added.

A limitation of the study was that researchers could not distinguish subtypes of atrial fibrillation such as persistent or permanent.

It is also possible that some cases of atrial fibrillation may have been missed among people who did not show any symptoms.

The study cemented a belief by Dr. Steven Kalbfleisch, an electrophysiologist at The Ohio State University Wexner Medical Center, that anticoagulants were not used as frequently as they could be.

Kalbfleisch, who specializes in the care of cardiac arrhythmia, told Healthline that some patients are resistant to the idea of taking anticoagulant medication.

“Anticoagulants are the gold standard for treatment,” Kalbfleisch said.

Part of his job is to educate patients on the benefits and relative risks of anticoagulant drugs.

Clinical evidence such as this latest study is useful in that regard.

In it, people with atrial fibrillation who were taking anticoagulants, or blood thinners, to keep their blood from clotting were actually less likely to develop dementia than those who did not take blood thinners.

People with atrial fibrillation may experience a greater risk of dementia than those without it.

Patients taking anticoagulants showed a lower risk of dementia. Not all patients are willing to take them, however.

“Good counseling can help patients understand the risks of not taking these drugs,” Kalbfleisch said.