February 1, 1999Open Access
View Full PaperMulticenter Clinical and Analytical Evaluation of the AxSYM Troponin-I Immunoassay to Assist in the Diagnosis of Myocardial Infarction
Structured PICO
What is the diagnostic accuracy of the AxSYM troponin I immunoassay for detecting acute myocardial infarction in patients presenting with chest pain?
P
Population
633 patients presenting with chest pain (122 with acute myocardial infarction), plus healthy individuals and patients with skeletal muscle injury, chronic renal disease, or same-day noncardiac surgery.
I
Intervention
AxSYM troponin I (cTnI) immunoassay
C
Comparator
Stratus cTnI, OPUS cTnI, and Access cTnI immunoassays
O
Outcome
Diagnostic sensitivity and specificity for acute myocardial infarctionsurrogate
The AxSYM troponin I immunoassay provides high diagnostic sensitivity and specificity for detecting acute myocardial infarction in patients with chest pain.
Abstract
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. Comparison of cTnI measurements between the AxSYM and Stratus (n = 406) over the dynamic range of the AxSYM assay demonstrated good correlation, r = 0.881, with a proportional bias: AxSYM cTnI = 3.50(Stratus cTnI) - 1. 10. The confidence intervals (95%) for the slope and intercept were 3.39-3.64 and -1.32 to -0.95, respectively. The expected cTnI concentration in healthy individuals was /=96%, in skeletal muscle injury, chronic renal disease, and same-day noncardiac surgery patients.