Abstract
Cardiac troponin I (cTnI) is a sensitive and specific biochemical marker of myocardial damage. We assessed the analytical performance of the Vidas® Troponin I assay (Biomerieux). Controls and serum pools were used to determine the precision, analytical sensitivity and linearity; 97.5 and 99.5 percentiles concentrations were determined from the reference population. Fifty corresponding samples of serum and plasma (lithium-heparin) were tested and the results compared. The in vitro stability of serum and plasma samples was assessed at 20 °C, 4 °C and -20 °C, respectively. Samples of serum were used to assess the agreement between the Vidas® Troponin I method and the revised Dimension RxL cTnI method (Dade-Behring). The total imprecision (CVs) was 13.1-5.2% for concentrations ranging between 0.25 and 19.8 µg/l cTnI. The lower detection limit was <0.1 µg/l. The upper reference limit (97.5 and 99.5 percentiles) was 0.11 µg/l and 0.12 µg/l, respectively (CV >10%). The assay was linear up to 21 g/l. The concentrations in lithium-heparin plasma were higher compared to those of the matched serum samples. The study of the agreement between the Vidas and Dimension RxL cTnI assays showed a total concordance of 96% with a bias value of -0.042. The Vidas® Troponin I test is a fast, precise and sensitive method for the determination of cTnI. Clin Chem Lab Med 2003; 41(10): 13631368
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