ANALYTICAL PERFORMANCE AND CLINICAL-APPLICATION OF A NEW RAPID BEDSIDE ASSAY FOR THE DETECTION OF SERUM CARDIAC TROPONIN-I

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.