Elevated levels of cardiac troponin T may prove effective as a risk predictor of ischemic heart disease, cardiovascular mortality, and diabetes, according to study results published in The New England Journal of Medicine (NEJM).
“Cardiac troponin concentrations are used to identify patients who would benefit from urgent revascularization for acute coronary syndromes. We hypothesized that they might be used in patients with stable ischemic heart disease to identify those at high risk for cardiovascular events who might also benefit from prompt coronary revascularization,” the study authors wrote.
Researchers used a high-sensitivity electrochemiluminescence assay to measure troponin levels in 2,285 study participants with type 2 diabetes and stable heart disease. Nearly 40% of these patients at the beginning of the study had elevated troponin levels (≥14 ng/L). Five years later, 27% of the high-risk individuals had died of stroke, heart attack, or other cardiovascular causes, compared with just 13% in the group with normal troponin levels.
Outcomes were especially poor in individuals whose troponin levels had risen higher than 25% during the study’s initial year.
“The patients in our study were not having symptoms of a heart attack, and yet a remarkably high proportion of them had an abnormal troponin, suggesting they were experiencing ongoing injury to their hearts,” said Brendan Everett, MD, MPH, an associate physician of the cardiovascular and preventive medicine divisions at Brigham and Women’s Hospital (BWH) and the study’s lead author, in a statement issued by BWH.
“In the future, if we can understand what causes the abnormal troponin, we may be able to identify new strategies to treat this group of high-risk patients,” Everett noted.
Researchers also determined that revascularization, a procedure that opens the coronary arteries of otherwise stable patients with elevated troponin levels and heart attack, had no perceived impact in reducing these levels—or in lowering the risk of cardiovascular-related death. The procedure was offered as a randomized treatment in this study.
Older men with a history of heart problems and chronic kidney disease tended to have higher levels of troponin than other study participants, an editorial in NEJM that discussed the study’s findings observed.
Its authors suggested that “elevated troponin levels should be evaluated in future trials of therapies for stable ischemic heart disease as a potential ‘enrichment’ factor (a factor that is used to specify inclusion criteria for clinical trials to enhance event rates in a randomized population) and should be compared with standard clinical enrichment factors such as older age, diabetes mellitus, and a history of cardiovascular events.”