Aldo Clerico¹, Martina Zaninotto², Maria Stella Graziani³, Monica Mion², Silvia Masotti¹, Concetta Prontera¹, Marco Migliardi⁴, Antonio Fortunato⁵, Mario Plebani^2
1Scuola Superiore Sant’Anna e Fondazione CNR Regione Toscana G. Monasterio Pisa
²Dipartimento di Medicina di Laboratorio, Azienda Ospedaliera Universitaria, Padova
³Sezione di Biochimica Clinica, Università di Verona
⁴Laboratorio Analisi, Azienda Ospedaliera, Ordine Mauriziano, Torino
⁵Patologia Clinica, Azienda Sanitaria Unica Regionale Marche, Area Vasta 5, Ascoli Piceno

All guidelines recommend that cardiac troponin I (cTnI) and T (cTnT) should be considered the preferred biomarkers for the differential diagnosis of acute coronary syndrome (ACS), and also that the 99th upper reference population limit value for cardiac troponins should be measured with an imprecision ≤10 CV%. However, only after the year 2006, some cTn methods showed analytical performances in accordance with the quality specifications required by guidelines. The cTn methods with the best analytical performances (currently named “high-sensitivity” methods) should be preferred for the early diagnosis of ACS and also for risk stratification of cardiovascular disease both in general population and cardiac patients. The most recent international guidelines recommend that two basic criteria are needed to define the characteristics required for cTn immunoassays in order to be defined as “high-sensitivity” methods. The first criterion is that the total imprecision (CV) at the 99th percentile value should be ≤10%. The second criterion is that these methods should measure cTn concentrations at least in 50% (and ideally >95%) of both healthy adult men and women with value above the assay’s limit of detection. The aim of this SIBioC document is to discuss some critical aspects related to definition of “high-sensitivity” cTn methods, including: analytical performance, pathophysiological interpretations, and clinical relevance of “high-sensitivity” cTn assays with particular attention to routine practice of clinical laboratories in Italy, recommending the use of an accurate terminology to avoid the usage of potentially misleading terms.