Abstract

Background: A rapid bedside whole-blood quantitative cTnT assay has recently been developed. We evaluated
the reliability of this test for the diagnosis of myocardial injury in patients with acute coronary syndrome (ACS).
Material/Methods: Whole-blood cTnT levels were measured in 96 patients with ACS using the Roche Cardiac Reader[sup]®[/sup] rapid bedside assay device, and the results were compared with serum cTnT levels in the same patients measured by the Roche Elecsys[sup]®[/sup] Immunoanalyzer. There were 50 patients with clinical evidence of myocardial injury and 56 without.
Results: From the qualitative point of view (reporting negative or positive tests), the results of the rapid bedside tests were identical to those obtained by the serum immunoanalyzer. From
quantitative the point of view, the rapid bedside tests could not measure exact values below
0.1 ng/ml (reported negative) or above 2.0 ng/ml (reported >2.0). The measurements made by the rapid bedside tests within the range of 0.1 to 2.0 ng/ml correlated well with those of the serum immunoanalyzer (Cardiac Reader[sup]®[/sup] cTnT=0.61, Elecsys[sup]®[/sup] cTnT+0.12; r=0.88), but their mean values were significantly lower (1.20±0.71 vs. 1.41±1.03, p=0.0007).
Conclusions: The rapid bedside cTnT assay correlates well with immunoanalyzer measurements between
the values of 0.1 and 2.0 ng/ml. However, they tend to give significantly lower values and fail
to give exact values below 0.1 and above 2.0 ng/ml, which may affect their performance in monitoring and managing patients with ACS, and limit their use in predicting outcome.

Keywords: Coronary Arteriosclerosis - diagnosis, Dose-Response Relationship, Drug, Heart Diseases - diagnosis, Heart Injuries - diagnosis, Immunoassay - instrumentation, Immunoassay - methods, Myocardium - metabolism, Reagent Kits, Diagnostic, Reproducibility of Results, Sensitivity and Specificity, Troponin I - blood, Troponin T - blood, Coronary Artery Disease - diagnosis, Dose-Response Relationship, Drug, Heart Diseases - diagnosis, Heart Injuries - diagnosis, Immunoassay - methods, Myocardium - metabolism, Reagent Kits, Diagnostic, Reproducibility of Results, Sensitivity and Specificity, Troponin I - blood, Troponin T - blood