Comparison of diagnostic performance of cardiac troponin I on the IMMULITEsystem with other automated troponin I assays in minor myocardial damage

An analytical and clinical evaluation of cardiac troponin I (cTnI) on the I MMULITE system is presented. The assay results were compared with those of the Stratus II and the Dimension RxL-HM. A between-run imprecision CV < 20% was found at a cTnI concentration of 0.23 <mu>g/L (functional limit of det ection). On the basis of a reference study including 215 patients without i schemic heart disease (97.5th percentile: 0.294 mug/L) and 36 patients clin ically classified as having stable angina pectoris (<0.22 <mu>g/L) a prelim inary cutoff level of 0.3 mug/L was defined. Assay linearity, sample stabil ity, influence of sample material and method comparison studies were perfor med. In patients with Duchenne's disease, chronic hemodialysis treatment, p ulmonary embolism, coronary artery bypass surgery and minimally cardiac sur gery the cTnI results of the IMMULITE agreed better with the Dimension RxL- HM than with the Stratus IT data. Of 142 samples from patients with unstabl e angina 67 samples were classified as cTnI positive with the IMMULITE, 76 with the Dimension RxL-HM, and 62 with the Stratus II. In conclusion, the n ew assay is sensitive for the determination of cTnI and easy to perform wit hin 45 min.