American researchers believe a new blood test could make it easier to spot older people at risk of heart failure.
It can detect tiny levels of troponin T, a protein marker for cell death damage to the heart.
University of Maryland scientists found the marker in two-thirds of people aged 65 and over who took part in a long-term heart study.
Lead researcher Dr Christopher deFilippi said: "We found that the higher the level of troponin, the greater the individual was at risk for symptoms of heart failure or death from cardiovascular disease over the next 10-15 years."
Troponin T is already used in emergencies to help confirm that a patient's chest pains are due to a heart attack, but until now has not been detectable in apparently healthy people.
The study involved more than 4,000 older people who were not hospitalised and had no symptoms of heart failure. Blood samples were analysed at the start of the study and again two to three years later. Each participant was then monitored for heart-related diseases for around 12 years.
During the follow-up, 1,279 participants experienced heart failure for the first time, and 1,103 heart-related deaths occurred.
The scientists found troponin T levels could change over time, rising in some individuals with a corresponding increase in their risk of heart failure or cardiac death. Conversely, the risks dropped in those whose blood samples showed a reduction in troponin levels.
The findings, presented at an American Heart Association meeting in Chicago, were published online by the Journal of the American Medical Association.