High-sensitivity troponin T (hsTnT)

High-sensitivity troponin T (hsTnT)

High-sensitivity troponin T (hsTnT): Currently troponins are the preferred biomarkers for the diagnosis of acute myocardial infarction. Current guidelines endorse the cut off point at 99th percentile for a healthy population provided the assay method has enough precision at this level. But many commercially available assays fall short at this threshold levels. But the newer assays known as high-sensitivity troponin T (hsTnT) have good sensitivity at this cut off levels with the recommended precision of less than 10 percent imprecision. This naturally brings in another question about the specificity of these low levels of troponin detected by high sensitivity assays. The 99th percentile cut off has been kept because of the documented increase in morbidity and mortality beyond this levels which is an important safety feature.

Januzzi JL et al evaluated hsTnT in relation to 64-slice coronary computed tomography coronary angiogram in those presenting with acute chest pain [High-Sensitivity Troponin T Concentrations in Acute Chest Pain Patients Evaluated With Cardiac Computed Tomography. Circulation. 2010; 121: 1227-1234]. It was cross sectional study involving three hundred and seventy seven patients with chest and low to intermediate risk of acute coronary syndrome, presenting to the emergency department. It was noted that hsTnT detected twenty seven percent more acute coronary syndrome cases as compared with the conventional cardiac troponin T (P=.001). hsTnT concentrations were found to be related to several factors like severity of coronary artery disease, left ventricular mass, left ventricular ejection fraction and regional wall motion abnormality.