Rapid Measurement of Cardiac Markers on Stratus CS

Abstract

Biochemical markers of myocardial damage are of fundamental importance in ruling in and ruling out diagnostic strategies for acute coronary diseases, particularly when electrocardiographic findings do not allow a diagnosis. An increasing body of evidence has demonstrated the value of strategies based on specific (cardiac troponin I or T) and sensitive [myoglobin (Myo)] assays in the diagnosis (1), prognosis, and monitoring (2) of patients with acute coronary syndrome. The impact of laboratory information on the management of patients has led to the development and definition of recommendations designed to reduce the therapeutic turnaround time, thus improving the medical outcome for patients. Because of the delay often associated with transport-related problems, the concept of point-of-care testing has been introduced for the measurement of cardiac markers (3). Some requirements, which seem to be of value in assuring quality for devices and diagnostic systems designed for point-of-care testing of cardiac markers, require whole blood or heparinized specimens for effective therapeutic turnaround time and must guarantee quantitative, accurate, and precise results comparable to those provided by central laboratories. The aim of our study, therefore, was to evaluate the analytical performance of the Stratus CS (SCS; Dade Behring), a fluorometric enzyme immunoassay analyzer based on solid-phase radial partition immunoassay technology, for quantitative measurement of creatine kinase isoenzyme MB mass concentration (CK-MB), Myo, and troponin I (TnI) in whole blood samples collected using lithium heparinate as anticoagulant. The samples may be processed automatically by the analyzer, which provides for centrifugation on board before the analytical phase, or heparinized plasma may be dispensed directly into a sample cup for analysis. Briefly, after the first antibody is added to a glass fiber paper linked to the dendrimer, the sample and the second antibody are pipetted. Finally, enzyme activity is started by the substrate wash solution with the simultaneous …