ارزیابی چند مرکزی آزمایش تروپونین اخیر برای تشخیص NSTEMI Multi-centre evaluation of recent troponin assays for the diagnosis of NSTEMI

1. Introduction Since the European Society of Cardiology (ESC) recommendations about myocardial infarction in 2012 and 2015, the main role of cardiac troponin (cTn) results has been confirmed in the diagnosis of non-ST elevation acute myocardial infarction (NSTEMI) [1,2]. In 2012, Thygesen et al. recommended a way in which to use high-sensitive cTn (HS-cTn) assays, based on two blood samples (one at admission or H0, and one 3 h later or H3), and the use of a specific delta change (either relative or absolute) between H0 and H3 [3]. Recently, this H0-H3 strategy was confirmed as a ‘universal’ algorithm for rule-in or rule-out of NSTEMI, for all cTn assays [2]; however, the delta change value was not specifically indicated for each cTn assay. Recent guidelines further suggest the use of a ruleout rapid algorithm, based on a single cTn measurement at admission (H0) and using low threshold values (the limit of detection (LoD) of the assay) [2]. However, this rapid exclusion algorithm is not recommended for all cTn assays [2]. In hospital laboratories and in point-of-care testing, cardiac troponin measurements are achieved by various assays, including “contemporary”, “sensitive” and “highly-sensitive” assays [4]. Briefly, the adjectives “contemporary”, “sensitive” and “highly-sensitive” are used when the analytical precision of the assay (calculated as the coefficient of variation [CV]) at the 99th percentile value is above, equal to or less than 10%, respectively. Due to the absence of standardisation, troponin results cannot be transferred from one assay to another, and individual cut-offs must be strictly used in the context of the troponin assay for which they were determined [4]. Few studies indicate delta change values for cTn assays in a single population, but most are reported for HS-cTn methods [3,5–7]. We thus aimed to compare, from both an analytical and a clinical view, the use of different cTn assays in a routine setting for the diagnosis of NSTEMI in emergency departments, in a single multi-centre population, in order to determine the diagnostic characteristics of each cTn assay following the recommended algorithms.