Multicentre evaluation of an immunological rapid test for the detection of troponin T in whole blood samples.
In a multicentre study we assessed the analytical and diagnostic performance of a rapid test (TROPT rapid test, Boehringer Mannheim; in the USA: CARDIACT) for cardiac troponin T compared to quantitative troponin T ELISA and creatine kinase-MB mass determinations. The rapid test requires 150 microliters of heparinized or EDTA whole blood; serum is not suitable. Interference testing with biotin, haemoglobin and 27 standard drugs yielded no significant influence in the physiological range. Skeletal muscle troponin T concentrations > or = 40 micrograms/l gave positive results with the rapid test. We used the rapid test for 369 samples from 203 patients with suspected acute coronary syndromes and compared the results to troponin T ELISA and creatine kinase-MB mass. 90 patients (44%) were primarily classified as having myocardial infarction by the WHO criteria. Twenty-two (20%) of the 113 non-myocardial infarction patients were unstable angina pectoris cases showing increased troponin T ELISA but not increased creatine kinase-MB mass values. Consequently, these were classified as minor myocardial damage cases. The rapid test was positive in 99% of all samples with a troponin T ELISA value > or = 0.30 micrograms/l and negative in 95 to 96% of all samples below this value. Diagnostic sensitivities for the detection of acute myocardial infarction within the first 12 hours after onset of pain were the same, 90%, for the rapid test, troponin T ELISA and creatine kinase-MB mass. After 48 hours, diagnostic sensitivity of creatine kinase-MB mass sharply decreased whereas that of the troponin T assays remained close to 100% beyond 72 hours after onset of symptoms. Diagnostic specificities for acute myocardial infarction (WHO) of all markers remained between 80 and 100% over this time. The diagnostic sensitivity of the rapid test for the detection of high risk unstable angina pectoris patients with minor myocardial damage was nearly the same as for troponin T ELISA. A major advantage of the rapid test is the ease of use and 20 minute turn around time. This facilitates the detection of increased troponin T at alternate sites.
Collinson
P O
PO
Mayday University Hospital, London, Great Britain.
Gerhardt
W
W
Katus
H A
HA
Müller-Bardorff
M
M
Braun
S
S
Schricke
U
U
Vogt
W
W
Nagel
D
D
Zander
M
M
Leinberger
R
R
Mangold
D
D
Zerback
R
R
D015415:Biomarkers / Q000097:blood*; D003402:Creatine Kinase / Q000097:blood; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007527:Isoenzymes; D018482:Muscle, Skeletal / Q000378:metabolism; D009203:Myocardial Infarction / Q000175:diagnosis; D009206:Myocardium / Q000378:metabolism*; D017285:Polymyositis / Q000097:blood; D051437:Renal Insufficiency / Q000097:blood; D012206:Rhabdomyolysis / Q000097:blood; D014336:Troponin / Q000097:blood*; D020107:Troponin T
D015415:Biomarkers; D007527:Isoenzymes; D014336:Troponin; D020107:Troponin T; D003402:Creatine Kinase