A high level of troponin - a protein normally used to exclude the possibility of a heart attack in patients with chest pain - may signal a heightened risk of death from any cause within the next few years, even in the absence of known or suspected cardiovascular disease, according to the research published in the journal Heart.
Findings by researchers at the University of Southampton, together with scientists from other organisations, suggest that troponin may have a more general role as an indicator of medium-term survival. High cardiac troponin levels are often seen in hospital patients who don't have specific signs of a heart attack, but the clinical significance of this has never been clear.
To explore this further, the scientists tracked the survival of 20,000 hospital patients who had had a blood test for any reason between June and August 2017 at a large teaching hospital, regardless of the original clinical indication, and in whom a troponin test was measured, even if there was no suspicion of heart disease. Their average age was 61 and more than half (53 per cent) were women.
Further analysis accounting for age, sex, hospital location, and kidney function revealed that an abnormally high cardiac troponin level was independently associated with a 76 per cent heightened risk of death not only from both cardiovascular disease but also other causes. In fact, the most common cause of death was cancer, followed by cardiovascular disease.
After excluding deaths that occurred within 30 days, a parameter used to define the likelihood that this was associated with the reason for their inpatient stay, the link between cardiac troponin and heightened risk of death persisted. This indicates that this association was not driven purely by a short-term risk of death, highlight the researchers.
Professor of Interventional Cardiology, Nick Curzen, from the University of Southampton, said: "This study suggests the troponin blood test, as distinct from its current role as a test for acute heart attack, may be useful in a much more general way as a snapshot indicator of medium-term mortality in all patients, regardless of whether they are known, or suspected, to have a heart problem.
"The especially fascinating finding is that the troponin snapshot was not just associated with death from cardiovascular causes, but also from cancer and other non-cardiovascular conditions."
