C. Heeschen et al., ANALYTICAL PERFORMANCE AND CLINICAL-APPLICATION OF A NEW RAPID BEDSIDE ASSAY FOR THE DETECTION OF SERUM CARDIAC TROPONIN-I, Clinical chemistry, 44(9), 1998, pp. 1925-1930
Detection of cardiac troponin I (cTnI) in patients suspected of having
an acute coronary syndrome is highly predictive for an adverse outcom
e. We evaluated a bedside test for cTnI that uses a polyclonal capture
antibody and two monoclonal indicator antibodies. Clinical studies we
re performed in patients with acute coronary syndrome and patients wit
h chest pain but no evidence of acute myocardial injury. The whole-blo
od, 15-minute assay had a concordance of 98.9% with an ELISA for cTnI
and a detection limit of 0.14 mu g/L, and the device tolerated tempera
tures between 4 degrees C and 37 degrees C. Diagnostic sensitivity for
myocardial infarction at arrival (3.5 +/- 2.7 h after onset of sympto
ms) was 60% [creatine kinase isoenzyme MB (CK-MB) mass, 48%; CK activi
ty, 36%; P < 0.01], and 4 h later, diagnostic sensitivity was 98% (CK-
MB mass, 91%; CK activity, 61%; P < 0.01). In 38% of the patients with
unstable angina, at least one positive cTnI test was found (CK-MB mas
s, 4%; CK activity, 2%). No false-positive test results were found in
renal failure or injury of skeletal muscle. We conclude that the diagn
ostic efficacy of the cTnI rapid test was comparable with the cTnI ELI
SA and superior to CK-MB determination. Therefore, this device could f
acilitate decision-making in patients with chest pain at the point of
care.