High-sensitivity troponin assays: analytical and clinical aspects
Cardiac troponins are considered the most sensitive and specific biomarkers for the diagnosis of acute coronary syndromes (ACS). According to the Third Universal Definition of Acute Myocardial Infarction, the diagnosis requires a rise / or fall of troponin concentration with at least one value exceeding the 99th percentile upper reference limit (URL) in a reference population with the coexistence of clinical symptoms of ischemia. The introduction of highly sensitive assays has resulted in lower detection limits for the concentration of troponin, allowing for early diagnosis of, as well as the detection of quantifiable concentrations of this biomarker in healthy subjects. According to current guidelines, the use of high-sensitivity tests can shorten the time required to make clinical decisions from the current 3-6 hours to 1-2 hours. The use of highly sensitive troponin assays also carries other potential benefits associated with their predictive value, as well as challenges that include reduced specificity for myocardial infarction, lack of standardization or the presence of biological variability. Given the increasing availability of new, highly sensitive troponin assays we should be aware that their increased analytical sensitivity and precision is accompanied by accurate clinical assessment of the patient, and takes into account other non-cardiac causes of their increased concentrations.