Clinical chemistry
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Multicenter Study
Multicenter clinical and analytical evaluation of the AxSYM troponin-I immunoassay to assist in the diagnosis of myocardial infarction.
We evaluated the AxSYM troponin I (cTnI) immunoassay for assisting in the detection of acute myocardial infarction (AMI). At four sites, the total imprecision (CV) over 20 days was 6.3-10.2%. The minimum detectable concentration was 0.14 +/- 0.05 microgram/L. ⋯ This gave a diagnostic sensitivity of 91.8% and specificity of 92.4% when tested in serial samples collected within 24 h of admission in 633 patients presenting with chest pain, of which 122 had an AMI. The concordances of the AxSYM cTnI with the Stratus cTnI, OPUS cTnI, and Access cTnI were 95.3%, 95.1%, and 94.3%, respectively, from patients with suspected AMI. The AxSYM cTnI demonstrated excellent clinical specificity, >/=96%, in skeletal muscle injury, chronic renal disease, and same-day noncardiac surgery patients.