The measurement of troponins in blood has rapidly become an alternative to conventional methods of detecting myocardial damage (1)(2)(3)(4)(5)(6)(7)(8), particularly in unstable angina, and several studies have indicated the prognostic importance of increased troponins in various clinical settings (9)(10)(11)(12)(13)(14). These studies, however, have also pointed out the need for more sensitive methods because patients with even small increases of troponin seem to be at increased risk of cardiac events. Currently, cardiac troponin I (cTnI) can be quantified by assays from several manufacturers (15)(16)(17)(18)(19), whereas only one company currently commercializes a cardiac troponin T assay (2)(20)(21). The aim of this work was to evaluate the analytical performance of a new generation of the Access cTnI assay. We also provide data on values in apparently healthy subjects. Venous blood was drawn from 70 patients admitted to our Coronary Care Unit because of suspicion of an acute coronary syndrome. Only patients found to have increased myocardial markers such as creatine kinase-MB and troponin I were included. The study was approved by the ethics committee of the Medical Faculty of Uppsala University. Serum samples were also obtained from 122 apparently healthy subjects (70 women and 52 men; median age, 41 years; range, 26–73 years) as part of a health-screening program. The new ACCESS cTnI assay (Beckman Coulter, Inc., Chaska, MN) is a two-site immunoenzymatic (sandwich) immunoassay. Paramagnetic particles coated with mouse monoclonal anti-cTnI, mouse monoclonal anti-cTnI-alkaline phosphatase conjugate, and sample are added to a reaction vessel to form a particle-cTnI-conjugate sandwich. The …
Venge et al. (Tue,) studied this question.