New research has found that atrial fibrillation (AF), an irregular and often abnormally fast heartbeat, appears to be linked to an increased risk of dementia, even in people who have not suffered a stroke.
Led by researchers at Yonsei University College of Medicine, Seoul, Republic of Korea, the new large-scale study looked at 262,611 people aged 60 or over, who were free of AF and dementia in 2004. The participants were then followed until the end of 2013.
The findings, which were published in the European Heart Journal Wednesday, showed that the participants who developed atrial fibrillation during the follow-up had a 50 percent increased risk of also developing dementia, compared to those who did not develop AF. This increased risk remained even after the team had removed the participants who had suffered a stroke from their calculations.
"This means that, among the general population, an extra 1.4 people per 100 of the population would develop dementia if they were diagnosed with atrial fibrillation. The risk occurred in people aged younger and older than 70 years," commented lead author Professor Boyoung Joung,
Atrial fibrillation also increased the risk of Alzheimer's disease by 30 percent and more than doubled the risk of vascular dementia.
The good news is that the researchers also found that AF patients who took oral anticoagulants to prevent blood clots, such as warfarin, or non-vitamin K anticoagulants, such as dabigatran, rivaroxaban, apixaban or edoxaban, had a 40 percent decreased risk of dementia compared to patients who did not take anticoagulants.
AF, also known as a heart flutter, is the most common heart rhythm disorder. The likelihood of developing the condition increases with age, and more than half of AF patients are aged 80 or older. Symptoms include chest pain, 'racing' or unusual heartbeat palpitations, weakness, fatigue, lightheadedness, dizziness, and shortness of breath and the condition increases the risk of stroke, other medical problems, and death.
The researchers say that this is the largest study to date to investigate the link between AF and dementia in people aged 60 and over who did not have AF or history of a stroke at the study.
The study also has the longest follow-up with an average of more than six years.
"With these large figures, we can be sure of our findings," said co-author, Professor Gregory Lip. "We also believe that our results can apply to other populations too, as they confirm similar findings of a link between atrial fibrillation and dementia in studies of people in Western and European countries."