Multisite study of a second generation whole blood rapid assay for cardiac troponin T

We evaluated a second generation, qualitative, whole blood rapid assay for cardiac troponin T (cTnT), which employs a more cardio-specific troponin T mouse monoclonal capture antibody. Using quantitative cTnT enzyme-linked immunosorbent assay (ELISA) results as the benchmark for accuracy, we compared the performance of the second generation and the original whole blood rapid assays in 445 samples from patients with the following diagnoses, determined by medical record review: myocardial infarction, coronary bypass surgery, ischaemic heart disease, musculoskeletal disease, renal failure or other noncardiac conditions. Overall, concordance between the second generation cTnT Rapid Assay and the quantitative cTnT ELISA, compared using the McNemar test and a cut-off concentration of 0.1 microgram/L, was in the range 76-94% for each patient group. Using a receiver operating characteristic plot, the cut-off for the second generation cTnT Rapid Assay was in the range 0.06-0.08 microgram/L. We conclude that the second generation cTnT whole blood assay has a 2.5-fold lower analytical cut-off than the original rapid assay (0.2 microgram/L) and may represent a more sensitive clinical tool for the rapid triage and risk stratification of cardiac patients.