Defining the serum 99th percentile in a normal reference population measured by a high-sensitivity cardiac troponin I assay

Objectives: This study determined the serum 99th percentile reference value for cTnI measured using the high sensitivity Erenna (R) cTnI assay. Design and methods: Serum was obtained from healthy adults (n = 348); aged 18-76 years of which 147 were males and 201 were females. Nonparametric analysis was performed to determine the 99th percentiles. Results: For all subjects, the 99th percentile was 10.19 ng/L; mean concentration = 1.45 ng/L, range = 0.2 to 34.56 ng/L. By gender, the male and female 99th percentile values were as follows: male = 16.58 ng/L, mean concentration = 1.72 ng/L, and female = 9.36 ng/L, mean concentration = 1.25 ng/L, respectively (p = 0.108). Conclusion: cTnI measured by the high-sensitivity Erenna cTnI assay measured 100% of normal subjects, allowing prospective diagnostic and risk assessment studies to be performed, which are essential for the early detection of cardiac disease and for the management of patients presenting with symptoms suggestive of acute coronary syndrome. (C) 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.