Cardiac troponin T predicts cardiac events in healthy middle-aged people
MedWire News: Cardiac troponin T (cTnT) levels measured by a highly sensitive assay may predict the risk for adverse cardiac events in middle-aged individuals without a history of cardiovascular disease (CVD), US study results indicate.
The study, which appears in the journal Circulation, was conducted by Christie Ballantyne, (Baylor College of Medicine, Houston, Texas) and colleagues, over a mean period of 10 years.
They found that when a highly-sensitive assay with a detection limit of at least 0.003 µg/l was used, circulating cTnT levels were detected in 66.5% (n=6449) of a group of 9698 CVD-free individuals aged 54-74 years old, reflecting an assay sensitivity 66 times higher than that of currently used fourth-generation assays.
Stratification of the participants into five groups based on cTnT levels, revealed that those with the highest cTnT levels in the group (≥0.014 µg/l) had 2.29-, 7.59-, and 5.95-fold higher 10-year risks for coronary heart disease (CHD), fatal CHD, and heart failure (HF), respectively than those with the lowest levels (<0.003 µg/l).
All-cause mortality risk was almost four times greater in the highest versus lowest group.
The team reports that even the smallest cTnT elevation detectable by highly-sensitive assay (≥0.003 µg/l) led to a significantly increased risk for mortality and HF, reflecting that "cTnT may be an important predictive marker."
Ballantyne and colleagues remark: "The stronger association of cTnT with death and HF than with CHD suggests that this biomarker predicts structural heart disease events to a greater extent than atherosclerotic events."
Further analysis revealed that the addition of cTnT elevation as a variable in CVD risk prediction models significantly improved the predictive accuracy of models, such as the ARIC (Atherosclerosis Risk in Communities) Coronary Risk Score model.
The degree of improvement observed when cTnT was added to risk models was similar to the effect of N-terminal pro-B type natriuretic peptide in such models, and greater than that of the addition of C-reactive protein.
"As HF prevalence and incidence continue to increase, markers such as cTnT may conceivably identify high-risk individuals and allow early initiation of preventive strategies," say Ballantyne et al.
They conclude: "Better understanding of the adverse mechanisms/processes that cTnT marks or mediates may be useful in targeting therapies."
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By Lauretta Ihonor