Analytical performances of the newly developed, fully automated Kryptor Copeptin assay: which impact factor for myocardial infarction rules out in the emergency department?

We evaluated the essential assay characteristics of the newly developed, fully automated Kryptor Copeptin assay including the assay performances and the clinical implications in parallel with the dosage of the cardiac Troponin I (cTnI) in patients presenting to the Emergency Department with chest pain with or without ECG abnormalities.Analytical performance of the B-R-A-H-M-S Copeptin Kryptor was carried out according to the CLSI protocol EP17-A, volume 24, number 34 [3] including linearity imprecision, determination of quantification, and detection limits. An evaluation of the clinical concordance between cTnI and copeptin results was performed on consecutive patients, with chest pain suggestive of acute coronary syndromes (ACS), admitted to the Emergency Department of our hospital.At a total imprecision of 20% (which corresponds to the limit of the quantification) and the level giving a CV of 10%, the functional sensitivity was approximately 10.4 and 23 pmol/L, respectively. The mean detection limit for the B-R-A-H-M-S Copeptin Kryptor assay was 8 pmol/L (range 5.57-10.37 pmol/L) in our study. Clearly, the combination of the cTnI and copeptin markers at the decision limit of 0.04 microg/L and 10.4 pmol/L, respectively, improves the diagnosis of exclusion of ACS.The combination of negative troponin and negative copeptin (quantification limit) could improve rapid sorting of ACS patients in an emergency. The Copeptin Kryptor assay is a useful diagnosis tool to rule out ACS and might be further enhanced by the recent development of sensitive troponins.