A simple blood test can predict if someone is going to have a heart attack up to six years before it occurs, researchers have said.
A team in America have adapted a test normally used to establish if someone if having a heart attack to predict one years in advance.
The development could allow those at high risk to take action such as adopting a healthier lifestyle and taking drugs to lower blood pressure and cholesterol levels.
The more sensitive test identified proteins in the blood that signal heart cells have been dying in seemingly healthy people with no outward signs of heart disease.
It was found that where the protein called troponin T were present, the patient was seven times more likely to die from heart disease within the next six years.
Dr James de Lemos, associate professor of internal medicine at Southwestern Medical Centre, at University of Texas and lead author of the study said: “This test is among the most powerful predictors of death in the general population we’ve seen so far.
“It appears that the higher your troponin T, the more likely you are to have problems with your heart, and the worse you’re going to do, regardless of your other risk factors.”
The findings are published in the Journal of the American Medical Association and follow on from an earlier study which suggested the protein could also predict heart failure, a condition where the organ fails to pump strongly enough causing breathlessness and fatigue.
The latest study involved more than 3,500 healthy people and 25 per cent were found to have detectable levels of troponin T.
They provided blood samples and underwent multiple body scans to examine their hearts and internal organs.
They found older people, men and African-Americans had the highest levels of troponin T along with those showing signs of thickening or weakness of the heart muscles.
They were then tracked for an average of seven years from 2000 to 2007 to establish how many people died, of what and when.
The more sensitive test can detect circulating protein levels in almost everyone with chronic heart failure and chronic coronary artery disease, the authors said.
Dr de Lemos said: “Because this test seems to identify cardiovascular problems that were previously unrecognised, we hope in the future to be able to use it to prevent some death and disability from heart failure and other cardiac diseases.”
Currently doctors use computer software calculations called the Framingham Score and Qrisk to identify people at high risk of heart disease who could benefit from preventive treatments. The calculations take into account family history, smoking history, cholesterol levels, blood pressure and age.
The earlier study, published in the same journal last month, found that troponin T levels could predict the chance of heart failure up to 15 years in advance.
Until now, no blood test has been able to give an indication of a person’s risk of heart failure.
The study conducted by University of Maryland involved 4,000 people whose blood was taken in 1989.
Prof Christopher deFilippi, the lead researcher, said: “We found that the higher the level of troponin T, the greater the individual was at risk for symptoms of heart failure or death from cardiovascular disease over the next 10 to 15 years.”
He added that those with the highest levels of troponin T were four to five times more likely to develop heart failure than those with the lowest detectable levels. People whose levels dropped over time appeared to reduce their risk of heart failure.