Evaluation and Comparison with Other High-Sensitivity Methods of Analytical Performance and Measured Values of a New Laboratory Test for Cardiac Troponin I Assay

Abstract

Bakground The aim of this study was to evaluate both analytical characteristics and clinical results of a new chemiluminescent method for the measurement of cardiac troponin I (cTnI), named VITROS ® High Sensitivity Troponin I Assay, using the VITROS® 3600 automated platform. The results found with this new method were compared to those observed with hs-cTnI ARCHITECT and ECLIA hs-cTnT ELECSYS methods. Methods For evaluation of analytical performance and comparison of clinical results, plasma samples (lithium-heparin), were collected from apparently healthy subjects and patients with cardiovascular diseases. Results The hs-cTnI VITROS method showed values for limit of blank (LoB 0.33 ng/L), limit of detection (LoD, 0.91 ng/L), limit of quantifications at 20% (LoQ 20% CV, 1.82 ng/L), and 10% (LoQ 10% CV, 4,74 ng/L), which are comparable to those previously reported for other hs-cTnI methods. Moreover, the clinical results of the hs-cTnI VITROS method were found to be closely correlated to those of hs-cTnI ARCHITECT (R = 0,9883, N = 198) and ECLIA hs-cTnT Elecsys (R = 0,9704, N = 293) methods. Conclusions The hs-cTnI VITROS method shows analytical performance comparable to other cTnI and cTnT assay. The results of this study confirm that there are significant systematic differences among hs-cTnI methods. Further multicenter studies using larger reference populations are needed in order to obtain a better estimation, especially of the 99° percentile URL values categorized for sex and age of hs-cTnI and hs-cTnT methods.

Cardiac troponins: Mechanisms of release and role in healthy and diseased subjects

“…10 Moreover, the commercial hs-cTnI assays show heterogeneous results due to the use of different antibody combinations in the different TnI assays, while only one commercial assay is available for TnT, making consistent and comparable the results across laboratories. 10,[37][38][39][40][41]…”

“…Only in the last 10 years, some immunoassay methods for cTnT and cTnI, able to meet the quality specification recommended by international guideline, have been commercialized 10 . Moreover, the commercial hs‐cTnI assays show heterogeneous results due to the use of different antibody combinations in the different TnI assays, while only one commercial assay is available for TnT, making consistent and comparable the results across laboratories 10,37–41 …”