The influence of implementation of the European Society of Cardiology guidelines on a number of troponin reports in emergency laboratory

BACKGROUND: According to the guidelines of the European Society of Cardiology (ECS), the diagnosis of acute myocardial infarction (AMI) is made according to criteria that include an increase in cardiac markers (troponin) with the presence of characteristic clinical symptoms or electrocardiogram changes or imaging of myocardial damage. At the Department of Emergency Medicine, University Hospital Centre Zagreb, the use of the ECS guidelines was introduced in year 2013. In an emergency laboratory high-sensitive troponin (hs-TnT) is used for determination of troponin (TnT). The guidelines define dynamic determination of TnT, i. e. at patient admission and after three hours. The decision cutoff point for definition of AMI is the 99th percentile in the general population with the coefficient of variation of less than 10%. The 99th percentile for the hs- TnT test that we routinely used is 0.014 µg/L and the lower detection limit is 0.003 µg/L. To facilitate physicians' understanding, we have provided the comment with each TnT report: "The values exceeding 0.014 µg/L indicate the presence of cardiac damage. In patients with clinically suspected AMI, changes in value ≥ 0.007 µg/L after 3 hours may assist in diagnosis confirmation“. The aim of this study was to investigate how the application of new guidelines affected the number of requests for determining TnT concentration. METHODS: We compared the number of patients for whom the TnT analysis was requested during three months in 2012 and 2013 and the number of released TnT reports in these periods. Data were taken from the laboratory information system. For statistical analysis, the chi- square test was used. RESULTS: The number of patients with requested TnT analysis in 2012 was 1109/1091/1046 and in 2013 it was 1150/1152/1134 (October/November/December, respectively). The number of released TnT reports in 2012 was 1267/1194/1186 and in 2013 it was 1402/1414/1407. Statistical analysis showed significant increase in the number of released TnT reports (p0.05). CONCLUSIONS: During the period of observation in 2013 there was a significant increase in the number of released TnT reports, which is attributed to the application of ECS guidelines.