Hidden heart disease in people with no symptoms could be detected using a new blood test developed by scientists.
The test can uncover whether a middle-aged person is at risk of dying young, even if they appear healthy.
It is a more sensitive version of a test that is already used to confirm whether someone is having a heart attack.
The test looks for low levels of a protein known as cardiac troponin T (cTnT) in the blood.
When US researchers screened 3,500 people, they found a positive reading in a quarter of the blood samples.
Those with detectable levels of cTnT were almost seven times more likely to die from heart disease within the next six years than those whose results proved negative.
Study leader James de Lemos, from the University of Texas, 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 standard test is only able to identify signs of heart disease in a very small percentage of the population, making it unsuitable for use as a screening tool.
The new test can detect circulating cTnT levels in almost everyone with chronic heart failure or coronary artery disease.
The research is reported in the Journal of the American Medical Association.