Heart attacks may soon be easier to predict thanks to a method of reading routine heart scans that can pinpoint those most at risk, research suggests.

Every year, roughly 750,000 Americans have a heart attack and around half die from it, often before reaching hospital. In the UK, someone has a heart attack every seven minutes. Doctors hope to identify the highest risk patients so they can be given preventative treatment and advised to adopt lifestyle changes.

Heart attacks normally occur when fatty plaques in the heart’s arteries become inflamed. “Inflammation weakens the wall of the fatty deposit and it can rupture, releasing its contents into the blood,” said Professor Keith Channon, an author of the latest study. “This can cause a blood clot, blocking vital blood supply to the heart muscle and causing a heart attack.”

But it’s difficult to measure how inflamed these arteries are, meaning those who could benefit from inflammation-lowering protective drugs may not receive them.

Now, researchers in Oxford in the UK and Erlangen in Germany say they have found a vital clue – and it’s in the way fat surrounding the heart’s arteries reacts to that nearby inflammation.

The team noticed that on CT scans from people at high risk of a heart attack, fatty deposits next to the heart’s arteries lit up with a very distinctive yellow and black colour pattern – something not seen in healthy controls.

“We discovered that inflammation inside the coronary arteries actually spills out and changes the consistency of the surrounding fat – and that we could measure that change on a simple CT scan using our new method of analysis,” said Charalambos Antoniades, associate professor of cardiovascular medicine at the University of Oxford, who led the study. The findings were confirmed when the researchers later used a more expensive, gold-standard test called a PET scan.

Writing in the journal Science Translational Medicine, the team also reveal that inflamed arteries appeared to “cool off” as patients recovered after a heart attack.

Marc Dweck, a cardiologist and imaging expert from Edinburgh University, who was not involved in the research, said the simplicity of the technique was exciting. “This is a really cool piece of research,” he said. “For the first time, we get a glimpse of how inflamed an artery is from a simple, five-minute CT scan.” Dweck added that if the results held up in larger studies, the approach could help to identify people who would benefit most from new, but expensive, treatments like the latest cholesterol-lowering drugs.

Professor Metin Avkiran, associate medical director at the British Heart Foundation which part-funded the study, was also enthusiastic. “If this technique lives up to its promise in larger numbers of patients, it could help people avoid a potentially fatal heart attack,” he said.