Researchers from the University of California, San Francisco, report that levels of high-sensitivity cardiac troponin T (hs-cTnT) are independently predictive of secondary events in outpatients with stable coronary artery disease (CAD). Each doubling in hs-cTnT level was associated with a 37% higher rate of cardiovascular events (HR, 1.37 [95% CI, 1.14 to 1.65], P=0.001), researchers report online in JAMA Internal Medicine.
“These findings suggest that hs-cTnT levels quantify an element of risk that is not captured by existing measures of cardiovascular disease severity,” says Alexis L. Beatty, MD, lead study author.
Standard serum cardiac troponin assays measure troponin levels during myocardial infarction, but troponin is usually undetectable in patients with stable heart disease. New high-sensitivity assays can detect cardiac troponin in stable patients. Elevated hs-cTnT has been shown to predict secondary events in patients with stable CAD, but it has not been clear whether the measure is independently predictive.
Beatty and colleagues measured serum concentrations of hs-cTnT and performed exercise treadmill testing with stress echocardiography in 984 patients with stable CAD who were then followed for a median of 8.2 years. Eighty percent of patients had detectable hs-cTnT. Higher initial troponin T levels were associated with greater inducible ischemia and worse left ventricular ejection fraction, left atrial function, diastolic function, left ventricular mass, and treadmill exercise capacity. During the follow-up, nearly one-third of patients experienced heart attacks or heart failure or died due to cardiovascular causes. Researchers concluded that the findings support the potential use of hs-cTnT as a marker of risk in patients with stable heart disease. Read the study abstract.
