Both the National Academy of Clinical Biochemistry (NACB) and International Federation of Clinical Chemistry (IFCC) recognize that the use of a cTn assay with an imprecision of < 20% (evidence based) at the 99th percentile will not lead to any significant patient misclassification if cTn is interpreted in relation to serial measurements. At that time no assays fulfilled these criteria. Analytical performance goals for cTn assays were first recommended in 2000 and integrated within the first Universal Definition of Myocardial Infarction, which recommended (expert opinion) that cTn assays used for diagnosing MI have an analytical imprecision with a coefficient of variation (CV) ≤ 10% at the 99th percentile. The analytical sensitivity of cTn assays has improved over time, allowing for detection of other etiologies and unmasking clinical conditions resulting in acute and chronic cTn elevations.Īn elevated cTn concentration in the presence of ischemia is defined as a measurement exceeding the 99th percentile of a reference group of normal, apparently healthy individuals. Cardiac troponin (cTn) has been the preferred biomarker of myocardial necrosis for over a decade and updates to the Universal Definition of Myocardial Infarction (MI) have maintained cTn (troponin T or I) as the biomarker of choice.
Biomarkers play an integral role in the care and diagnosis of patients with acute myocardial infarction (AMI).
