Genetic test identifies people at higher risk of atrial fibrillation
13 October 2014
People who are genetically predisposed to develop atrial
fibrillation, which increases risk of stroke, can be identified with
a blood test according to research at Lund University in Sweden.
Over recent years, a research group at Lund University in Sweden,
working with other universities and hospitals in Europe and the USA,
has identified twelve genetic variants in the human genome that
increase the risk of atrial fibrillation. The research group has now
studied the possible clinical benefits of a DNA test:
“One in five people have a genetic weakness that means they have
twice as high a risk of developing atrial fibrillation as those with
a low genetic risk. This genetic risk is therefore one of the
strongest risk factors for atrial fibrillation that we know of in
people without overt cardiac disease. It increases the risk as much
as high blood pressure, for example”, said Olle Melander, Professor
of Internal Medicine, and Gustav Smith, Associate Professor in
Cardiology, both from Lund University.
Since the symptoms of atrial flutter can be weak and unclear,
they are sometimes difficult to pick up. However, even those with
weak or absent symptoms of atrial flutter are at significantly
higher risk of stroke.
“In patients who are suspected of having temporary but recurrent
episodes of atrial fibrillation, or in people with high blood
pressure, it can be important for doctors to look at their genetic
predisposition using a blood test. The test can give guidance as to
how often and how intensively doctors need to screen for presence of
atrial fibrillation in these individuals. We also consider that more
widespread treatment of high blood pressure may be justified in
those with a high genetic risk of atrial fibrillation”, explained
Patients already diagnosed with atrial fibrillation were also
studied, and the researchers observed that if they had the risk
genes, their risk of stroke was increased by a further 70–80%.
If an individual with atrial fibrillation is regarded as having a
sufficiently high stroke risk, lifelong treatment with anticoagulant
drugs such as warfarin is required in order to lower the risk.
“There are also benefits of checking the genetic risk of those
who have already been diagnosed with atrial fibrillation. The test
makes it easier to correctly assess whether anticoagulant medication
is necessary to prevent stroke, especially for those under 65”, said
The research data was taken from a long-term follow-up of 27,400
participants in a population study.
“The present results are one of several examples of how genetics
research is not only an effective way of identifying new disease
mechanisms, but can also have clinical applications and help doctors
and patients to decide on the right tests and treatment”, said Olle
Hayato Tada et al. Twelve–Single Nucleotide Polymorphism Genetic
Risk Score Identifies Individuals at Increased Risk for Future
Atrial Fibrillation and Stroke. Stroke, American Heart Association,
published online 14 Aug 2014.