People with a common heart rhythm problem are at a much greater risk of having a stroke and developing dementia than previously thought, a study suggests.
Atrial fibrillation (AF), an electrical fault that causes a fast or irregular heartbeat, affects 1.4 million people in Britain. Celebrities like Elton John, Miley Cyrus, Tony Blair and Joe Biden are among those known to suffer from it.
The condition has long been known to increase the risk of stroke because patients are more likely to develop blood clots that increase circulation to the brain.
For this reason, those most at risk are given blood-thinning medications to prevent an attack.
But researchers now believe that even those who are considered low risk — and don’t get a blood thinner — are more likely to have serious health problems.
Miley Cyrus is known to suffer from atrial fibrillation, an irregular heartbeat that affects 1.4 million people in Britain
Elton John’s irregular heartbeat was so severe that he needed a pacemaker
A team from the University of Birmingham examined data from more than five million people registered with British GP practices.
Among them, they identified 36,340 AF patients who had no history of stroke, had a low perceived risk of stroke, and had no prescription for blood thinners.
They were followed for an average of five years to assess their risk of stroke, vascular dementia or death. Their data was compared with information from 117,000 healthy people without AF.
Despite being in the low-risk group, about 3.8 percent of AF patients had a stroke, compared to 1.5 percent of healthy people.
And people with the condition were 68 percent more likely to develop vascular dementia, a form of the disease linked to problems with circulation in the brain.
According to the study, published in the journal Nature Medicine, nine percent of people with AF died, compared to five percent of healthy people.
Dipak Kotecha, professor of cardiology at the University of Birmingham and senior author of the study, said: ‘Atrial fibrillation is one of the most common heart diseases, with more than 60 million cases expected worldwide by 2050.
‘As prevalence continues to rise, it is critical that we develop strategies to prevent not only stroke, but also outcomes such as dementia, which are of major concern to patients and healthcare systems.
‘Our research underlines the urgency of a comprehensive approach to AF, taking into account its overall impact on patient well-being.’
Alastair Mobley, researcher at the University of Birmingham, said: ‘This study shows a clear correlation between AF and vascular dementia.
‘This may have a similar mechanism to the association between AF and stroke.
‘Ongoing clinical trials are investigating whether blood thinners in lower-risk patients could provide a way to prevent these poor outcomes.’
Atrial fibrillation is a heart condition that causes an irregular and often abnormally fast heartbeat. In some cases, people with the condition have a heart rate of more than 100 beats per minute.
It is the most common heart rhythm disorder. The condition has been linked to blood clots and there are ‘numerous’ tools to estimate stroke risk in people with AF, but researchers said they have only ‘modest predictive power’ and do not take into account other outcomes such as vascular dementia.
The authors highlight how guidelines from the National Institute for Health and Care Excellence and others recommend the use of anticoagulants only in patients with an increased risk score for stroke.
They said more studies are needed to assess whether patients with AF could benefit from earlier use of blood thinners to prevent these poor outcomes.