Evaluation of the Cardiac reader~(R) as a point-of-care instrument for measurement of fibrin D-dimers in dogs

摘要

Objective: The aim of this study was the evaluationof the automated point-of-care analyzer Cardiac reader~(R) for quantitative fibrin D-dimer measurement compared to the Liatest~(TM) D-Di~(TM) run on the bench top analyzer STA Compact (all Roche). Material and methods: 41 fresh canine blood specimens submitted from the Clinic for Small Animals, Justus-Liebig-University Giessen were included. Measurement of fibrin D-dimers with the Liatest~(TM) D-Di~(TM) immunoturbidimetric assay was performed in citrated blood plasma stored at -80 °C until analysis. Using the Cardiac reader, D-dimer plasma concentrations were measured with an immunological assay in heparinized fresh (< 1 hour) whole blood specimens. Results: Mean intra-assay coefficient of variation (CV) was 6.13% (range: 2.2-10.0%) for the Liatest~(TM) D-Di and 19.8% (range: 20.1-19.6%) for the Cardiac reader. Fibrin D-dimers detected with the STA Compact exceeded the upper limit of the reference interval (0.4 u.g/ml; n = 62 healthy dogs) in 20/41 samples. There was a fair correlation between D-dimer measurements with the Cardiac reader and the comparison method (r = 0.78). Generally, results were underestimated with a mean proportional bias (0.45 (ig/ml). The area under the Receiver Operating Characteristic (ROC) curve was 0.895 regarding the detection of increased fibrin D-dimers with the Cardiac reader. At a cut-off value of > 0.2 mu g/ml, sensitivity/specificity were 85%/91 % and positiveegative likelihood ratios were 8.93/0.17. At a lower cut-off value of 0.15 jig/ml sensitivity and specificity were 90% and 66%, respectively. Conclusion and clinical relevance: The Cardiac reader can be used for quantitative measurement of canine D-dimers, however, due to the odds of false negative results and the high imprecision the comparison method should be preferred.