Variation of Cardiac Troponin I and T Measured with Sensitive Assays in Emergency Department Patients with Noncardiac Chest Pain

Abstract

BACKGROUND: New-generation high-sensitivity assays for cardiac troponin have lower detection limits and less imprecision than earlier assays. Reference 99th-percentile cutoff values for these new assays are also lower, leading to higher frequencies of positive test results. When cardiac troponin concentrations are minimally increased, serial testing allows discrimination of myocardial infarction from other causes of increased cardiac troponin. We assessed various measures of short-term variation, including absolute concentration changes, reference change values (RCVs), and indices of individuality (II) for 2 cardiac troponin assays in emergency department (ED) patients.

Weekly and 90-Minute Biological Variations in Cardiac Troponin T and Cardiac Troponin I in Hemodialysis Patients and Healthy Controls

“…Another reason for the low CVi values in the current study is that the adjustment of the data to establish a steady state provides lower values compared to the noncorrected data used in other studies. However, the 90-min asymmetric RCV value (i.e., including CVa and CVi, and adding the ␤ value corresponding to the systematic decline) was similar to the RCV values found in some studies (17,21,23 ) and lower than those found in others (16,18,19,22 ).…”

Short- and Long-term Individual Variation in Cardiac Troponin in Patients with Stable Coronary Artery Disease

“…Studies of healthy individuals so far have shown the short-and long-term biological variations of cardiac troponin to be in the range of 3%-48% and 3%-117%, respectively; the short-term RCV has ranged from 44% to 113% and the short-term log-normal RCV for rising concentrations from 45% to 90% (12-15, 26, 27, 29 ). Similarly, in a recent study of patients presenting with chest pain in an emergency department, excluding patients with known stable angina, the individual variation was similar to that in healthy controls at 11% for cTnI and 18% for cTnT (28 ). In another recent study of patients with stable cardiovascular disease, the long-term CV i of cTnI was 28%, and log-normal RCV for rising and falling concentrations 98% and Ϫ50%, respectively, very similar to the long-term results in the present study (29 ).…”

High-sensitivity cardiac troponin assays: Answers to frequently asked questions

“…Troponin T responded the same way with the hs-cTnT assay [27]. The short-term RCVs measured by ARCHITECT (Abbott), Vista (Siemens), Access 2 (Beckmann) and Centaur (Siemens) assays are around the 50% range [27]. The RCV of hs-cTnT varies in the 38-58% range, depending on the study [27,28].…”

“…Wu et al studied short-term (within-day) and long-term (between-day) biological variation in hs-cTnI (Singulex ® assay) in healthy subjects [26], and found that cTnI demonstrates low intraindividual variation, but high interindividual variation -in other words, cTnI shows high-individuality. Troponin T responded the same way with the hs-cTnT assay [27]. The short-term RCVs measured by ARCHITECT (Abbott), Vista (Siemens), Access 2 (Beckmann) and Centaur (Siemens) assays are around the 50% range [27].…”

“…The short-term RCVs measured by ARCHITECT (Abbott), Vista (Siemens), Access 2 (Beckmann) and Centaur (Siemens) assays are around the 50% range [27]. The RCV of hs-cTnT varies in the 38-58% range, depending on the study [27,28]. Note that the RCV calculation can be applied to relative change variations (in ng/L) or absolute change variations (in %) (see 'Elevated hs-cTn values and infarct size').…”