Analytical characterization and clinical performance evaluation of a new point-of-care testing system for high-sensitivity cardiac troponin I assay

Abstract

Background We aimed to evaluate the analytical performance and clinical diagnostic accuracy of the SuperFlex point-of-care testing (POCT) high-sensitivity cardiac troponin I (hs-cTnI) assay system. Method The imprecision, the limit of blank, the limit of detection, the limit of quantitation, linearity and comparability were assessed as per the Clinical and Laboratory Standards Institute guidelines. Also, the 99th-percentile reference value and diagnostic accuracy were evaluated. Results The reproducibility and total imprecision were 1.52–1.92% and 2.69–2.92%, respectively. Limit of blank and limit of detection were 1 ng/L and 1.8 ng/L, respectively, and limit of quantitation was 12 ng/L at 10% coefficient of variation (CV). The results met the requirements of linearity, and the correlation coefficient was 0.996. The SuperFlex POCT results had good agreement with those obtained by the Siemens Advia 2400. The CV% was 7.24% at the 99th percentile concentration (p99th) of 25.6 ng/L (95% confidence interval: 22.0–33.3 ng/L) from 620 healthy subjects. The sex-partitioned CV% and p99th were 7.15% at 27 ng/L (males; n = 308) and 7.35% at 24 ng/L (females; n = 312), respectively ( P < 0.0001). The hs-cTnI detection rate of all observed healthy individuals from limit of detection to 99th was 82.57% by the SuperFlex POCT assay, 89.90% for the males and 75.48% for the females. The sensitivity, specificity, positive predictive value and negative predictive value of diagnostic performance for acute myocardial infarction were 100%, 81.25%, 57% and 100%, respectively. Conclusions The SuperFlex POCT system showed the analytical performance characteristics required for enabling the clinical use of a hs-cTnI assay.