Light-bulb moment at the kitchen table: a test for stroke risk

And their idea eventually turned into a research project in which one of the goals is to find a biomarker that can be easily measured in the blood, and which can reveal if the person is at an increased risk of stroke.

Want to predict a stroke before it happens

In her job as a physician in the cardiology clinic at University Hospital, Julia Aulin encounters patients with atrial fibrillation on a daily basis. Not so surprising considering that it is the most common type of abnormal heart rhythm, or arrhythmia, in the world. Many people who suffer from atrial fibrillation are treated with blood thinners to prevent blood clots in their brains. But a dilemma with this treatment is that it entails an increased risk of bleeding. This is what Julia Aulin would like to avoid.

“The focus of our research is on being able to better predict which individuals can benefit the most from blood-thinning treatment. Ultimately, we want to be able to predict a stroke before it happens. Because we want to be able to prevent a clot in the brain without causing an intracranial haemorrhage in the process,” says Julia Aulin.

She explains that the heart and brain are closely connected. With the condition atrial fibrillation, the heart is unable to pump all the blood around the body properly, which causes the blood to have an increased tendency to coagulate in the heart. These clumps of coagulated blood can then get into the bloodstream and cause clots in the brain.

Measurable protein

In a study of 3,000 patients with atrial fibrillation from around the world, she and her research colleagues discovered that the presence of neurofilaments, a kind of protein, in the blood appear to be associated with an increased risk of blood clots in the brain. Neurofilaments are normally found in the brain’s nerve cells, but if they get damaged, this kind of protein can leak out into the bloodstream.

“We could clearly see that higher levels of this brain protein, which we measured in the blood, meant an increased risk of stroke over the 18 months that we monitored the patients. If you belonged to the group with the highest levels of neurofilaments in your blood, then you were between three and four times more likely to have a stroke caused by a blood clot in the brain,” explains Julia Aulin.

When all the data was fed into models, high levels of neurofilaments appeared to be by far the greatest risk factor for a stroke of this kind, even greater than the most well-established risk factors: older age and previous stroke.

Although the results have so far been unambiguous, more studies are needed to confirm that this is true before this method of testing for stroke risk can be made widely available in the health care system.

“This is a step on the way to determining who benefits most from blood-thinning medication. Because stroke is very serious, we ultimately hope it can save lives. And in the longer term, we believe that this test could be a way to measure brain health in other individuals who seek medical care for cardiovascular conditions. We may be able to identify people at an early stage who have an increased risk of developing cognitive impairment or dementia, for example,” she says.

Defended her thesis during the pandemic

Julia Aulin has a number of hectic years behind her. She defended her thesis in the middle of the pandemic, during the same period as she and her colleagues at the cardiology clinic were labouring under a very heavy workload. With three young children at home, it was difficult, to say the least, to make everyday life function because her husband Karl Sjölin also had a heavy workload with a lot of emergency duty. Despite the fact that it was a hectic period, Julia Aulin felt she could not let go of the idea of a blood test to measure brain health. It would be a great help in her clinical work on a daily basis. So, in her spare time, she applied for research grants to be able to get the project started, and eventually received funding from Hjärt-Lungfonden.

She is as passionate about her research as she is about her job as a cardiologist, and she sees no contradiction between her two professional roles. Quite the opposite.

“It’s just such a privilege to be able to be on emergency duty and meet these patients in the emergency care department, and on the other hand be able to think about and see other approaches to their problem. That’s the best combination there is. And that’s also the challenge I should add: finding a balance between research and clinical work, because you only have 24 hours in a day,” says Julia Aulin.

Åsa Malmberg