High-sensitivity troponin T predicts CV risk in healthy men
MedWire News: Levels of high-sensitivity cardiac troponin T (hsTnT) predict cardiovascular disease (CVD) risk in asymptomatic middle-aged men, a population study has found.
The investigators suggest that hsTNT may represent a novel CVD risk marker (CVD) for use in primary prevention, adding to its established roles in risk-stratification and diagnosis in acute coronary syndromes.
A team led by Toshiaki Otsuka (Nippon Medical School, Tokyo, Japan) evaluated the ability of hsTnT levels to predict CVD risk in an ostensibly CVD-free population.
“Recent advances in medical technology have enabled the measurement of lower serum or plasma levels of TnT than the lower limit of the conventional assay by using a newly developed, highly sensitive assay (hsTnT),” they explain in the American Heart Journal.
“Recent studies have shown hsTnT to maintain a prognostic value at previously undetectable concentrations.”
They used this new assay to measure hsTnT levels in 1072 men taking part in a worksite-based study. The participants’ mean age was 44 years and none had any history or presence of CVD.
Levels of hsTnT were detectable (≥0.002 ng/mL) in 80.9% of the cohort. The highest value was 0.020 ng/ml, 2.2% of men had levels ≥0.010 ng/ml, and the median value was 0.004 ng/ml.
None of the participants had detectable TnT levels according to the conventional assay, the researchers remark.
Interestingly, hsTnT levels varied according to the presence of CVD risk factors, being significantly higher in men with hypertension, obesity, left ventricular hypertrophy, current smoking, or chronic kidney disease than in men without these features.
Similarly, hsTnT levels varied according to the overall CVD risk burden, being significantly higher in men at high CVD risk (as predicted by the Framingham algorithm) than in those at either intermediate or low CVD risk.
Finally, in multiple logistic regression analysis, men in the highest tertile of hsTnT (≥0.005 ng/ml) had a nearly four-fold increased risk for CVD (as predicted by Framingham) than did those in the lowest tertile (≤0.002 ng/ml), after controlling for multiple potential confounders.
The study authors conclude that a “substantial proportion” of men without overt CVD have slightly elevated hsTNT levels, and that this elevation is associated with several CVD risk factors and the 10-year predicted risk for CVD.
“These results suggest the usefulness of measuring hsTnT to identify high-risk subjects in the primary prevention of CVD,” they write.
In an accompanying editorial, Harvey White (Auckland City Hospital, New Zealand) said that the study by Otsuka et al helps to define what constitutes “normal” hsTnT levels in the community but does not identify a clinically meaningful hsTnT cutoff point for use in primary prevention or provide any information to guide patient management.
“Additional basic and clinical studies are required to elucidate the cellular mechanisms for the release of troponins and the impact on patient outcomes to aid our understanding of what elevated troponin levels mean in apparently healthy individuals,” he wrote.
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By Joanna Lyford