A group of researchers in the U.K. reported this week that even slight increases in a person’s cardiac troponin levels predict adverse outcomes—including early death—in patients of all ages.
Amit Kaura, lead author of the study and a National Institute of Health Research (NIHR) clinical research fellow, and colleagues studied the CV data of 250,000 patients who had troponin tests at NIHR-Health Informatics Collaborative (NIHR-HIC) sites between 2010 and 2017. They reported their findings in the British Medical Journal.
Troponin is integral to heart function, and Kaura et al. said that in general, it’s assumed that the higher a person’s blood level of troponin, the higher their risk of death. But it’s been unclear how physicians should manage patients with smaller spikes in their troponin—especially if they don’t present with an MI or other heart symptoms.
Kaura’s team analyzed the data of a quarter of a million patients who were treated across five NIHR-HIC centers in an effort to investigate both the significance of small troponin increases and the effect of troponin increases in all age brackets. They grouped their patients by age and compared their troponin levels with outcomes over three years.
The researchers found that in young patients (those aged 18-29 years), raised troponin levels, even if they were minor, indicated a 10-fold increased risk of death. That heightened risk decreased with age, eventually reaching a 1.5-fold increased risk in patients aged 90 and up. But even in very elderly patients, raised troponin was a predictor of mortality; nearly half of people over age 80 with elevated troponin levels died within three years of follow-up.
Contrary to their expectations, Kaura and colleagues also found that in patients whose “very high” troponin levels could be attributed to a heart attack, elevated troponin was actually associated with a lower risk of dying. In a release, Kaura said that could be because many patients with very high troponin levels are likely to have a type of heart attack that’s easier to treat with surgery, reducing their risk of death.
“There have been many advances in treating heart disease, yet it remains the leading cause of death in the U.K. and around the world,” Kaura said. “This is the first study to address the implications of raised troponin in a real-world large sample of patients across a wide range of ages. Doctors will be able to use this information to help identify the risk of early death in patients who have a troponin level measured; this could lead to interventions at a much earlier stage in a wider group of patients than are currently treated.”