Research
New blood test improves heart attack and stroke risk prediction
A simple £5 blood test for the protein troponin could allow doctors to predict a person's risk of heart attacks and strokes with greater accuracy than ever before, according to research funded by us and published today in the Journal of the American College of Cardiology.
Troponin is found in heart muscle cells and is released into the blood when the heart is damaged. High-sensitivity troponin blood tests, which are currently used in hospitals to diagnose heart attacks, can also detect silent ongoing damage to the heart, a sign of a future risk of cardiovascular disease. The tests can be done alongside routine cholesterol tests at GP surgeries.
Now, a study has found that people with higher levels of troponin in their blood are at greater risk of a heart attack or stroke within 10 years. The researchers’ modelling suggests that, for people currently found to be at intermediate risk on routine cardiovascular health assessments, the tests would prevent one heart attack or stroke for roughly every 500 people tested.
Up to four times more accurate
Researchers analysed anonymised health data of over 62,000 people from 15 studies in Europe and North America. Each person had their troponin levels measured, as well as conventional risk factors such as age, blood pressure, history of diabetes, smoking status and cholesterol levels. Participants were then tracked for around 10 years to see if they had a heart attack or stroke.
Current cardiovascular health assessments use an algorithm to predict their risk of having a heart attack or stroke in the next 10 years based on their risk factors, including cholesterol levels measured using a blood test. By adding troponin results to these conventional risk factors, the researchers found the algorithm’s predictions were up to four times more accurate than adding cholesterol results alone.
Crucially, the researchers’ modelling showed that the troponin test was especially effective at spotting danger in the 35 per cent of people currently assessed and found to be at intermediate risk of cardiovascular problems. Depending on their age, people with a 2.5 per cent to 15 per cent chance of having a heart attack or stroke within 10 years are said to be at intermediate risk.
The intermediate risk group presents medical professionals with a problem, as they are not at low risk, but the risk is not high enough to justify preventative treatment.
The modelling found that including the troponin tests meant that up to 8 per cent of people originally classified as intermediate risk were changed to high risk. Giving preventative treatments like statins to these reclassified people would prevent many serious cardiovascular events, including heart attacks or strokes.
"A powerful indicator of silent damage"
Professor Anoop Shah, Professor of Cardiovascular Medicine at the London School of Hygiene and Tropical Medicine and the lead author of the study, said:
“Troponin, even in the normal range, is a powerful indicator of silent heart muscle damage. As such, the test provides an extra layer of information that we can use to boost our accuracy when predicting people’s risk. We want to identify as many high risk people as possible, so that no-one misses out on the opportunity to get preventative treatment.
“Incorporation of troponin into current cardiovascular risk estimation guidelines can be useful for identifying high risk individuals who will benefit from preventative treatment, reducing the risk of future circulatory problems.”
Professor Bryan Williams, our Chief Scientific and Medical Officer, said:
“Developments in risk prediction have helped doctors to build effective algorithms that can spot those most at risk of heart attacks and strokes. But, with around 100,000 hospital admissions for heart attacks alone in the UK each year, it’s clear that there is still plenty of room for improvement.
“This new data suggests adding this blood test to current risk prediction models could help medical professionals identify more people who are at higher risk and deliver advice and treatment to reduce their risk of future heart attack and strokes.”