Specifiche di qualità, terminologia e definizione dei metodi di misura delle troponine cardiache I e T
Aldo Clerico1, Martina Zaninotto2, Maria Stella Graziani3, Monica Mion2, Silvia Masotti1, Concetta Prontera1, Marco Migliardi4, Antonio Fortunato5, Mario Plebani2 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
Quality specifications, terminology and definition of the methods for the measurement of cardiac troponins
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.