A new system for quantitative determination of troponin T and myoglobin in the emergency room and in the intensive care unit

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We present here the results of a multicentre evaluation of a small system (Cardiac reader) for the rapid and quantitative determination of troponin T (CARDIAC T Quantitative test) and myoglobin (CARDIAC M test) in heparinized venous whole blood (150 μl). The measuring unit of the Cardiac reader contains a CCD camera that optically reads the signal and the control line of the respective immunochemical test strips. The tests have a reaction time of 10 or 14 min. The quantitative measuring range for the troponin T determination on the Cardiac reader is 0.1 to 3 μg/l and 30 to 700 μg/l for CARDIAC M.

The within-series imprecision was very acceptable for CARDIAC T Quantitative (CV 10 to 15%) and good for CARDIAC M (CV 5 to 10%). Compared with the Enzymun-Test Troponin T, the results obtained with CARDIAC T Quantitative show a high correlation (n = 40; r = 0.967; y = -0.006 + 1.093x). The method comparison between CARDIAC M and Tinaquant^® Myoglobin shows that both assays agree well (n = 82; r = -0.959; y = 3.6 + 0.976x).

To assess the clinical efficiency, CARDIAC T Quantitative results of all five study centres (481 samples of patients with suspected acute coronary syndromes) were evaluated in a nine-field comparison table versus Enzymun-Test Troponin T. More than 90% clinical concordance were achieved with only 4 results that were clinically grossly discordant (0.8%); the corresponding Enzymun-Test Troponin T results were moreover directly at the cut-off point (0.10 mg/l). Sensitivity and specificity relative to Enzymun-Test Troponin T were 97 and 96%, respectively.

With the Cardiac reader reliable quantitative results can be easily obtained for both cardiac markers and entered into the hospital data system. Consequently, the Cardiac reader is especially suitable for use in emergency rooms and coronary care units.