Results from healthy donors for novel point-of-care high-sensitivity troponin test

Type of funding sources: None.

This study evaluates healthy donor values of a novel high-sensitivity troponin test, an 8-minute whole blood assay performed with fingerstick or Lithium-heparin samples using a handheld sized platform designed for Point-of-Care or in-lab measurements. In accordance with the Fourth Universal Definition of Myocardial Infarction, whole blood 99th percentile upper reference limits (URLs) and 50th percentile (median) values for healthy individuals were characterised per gender; values were established for fingerstick, venous whole blood, and plasma.

To determine 99th percentile URLs for hs-cTnI in healthy donors as myocardial injury cut-off for use in clinical trials and clinical practice. The median values were determined to confirm high-sensitivity performance in all matrices.

Whole blood from consented healthy subjects, 22 to 85 years (n=810), were collected across 5 clinical sites. Subjects taking cardiac history/medications or having abnormal hemoglobin A1c, NT-proBNP, and eGFR values were excluded. hs-cTnI values were determined in capillary (fingerstick), Li-Heparin venous whole blood, and venous Li-Heparin plasma matrices. Sex-specific and overall 99th percentile URLs using the recommended non-parametric approach and median values for each sample matrix were determined.

Statistical outliers were eliminated by the Dixon-Reed test, prior to calculating the 99th percentile and median values. There was no significant difference between the three sample types. The median results are tabulated below: as expected, the female values are lower than the male values (p <0.01). These data additionally show that >50% of results exceed the assays limit of detection [ref .1] for all matrices, confirming this assay is a high-sensitive assay for troponin-I.

The novel hs-cTnI system is the first that demonstrates high-sensitivity cTnI performance in fingerstick, whole blood and plasma matrices. Quality measurements in all three matrices translates to use with confidence in emergency department and other diagnosis and triage settings. Hence, the data presented here are of relevance to current and future studies and clinical implementation of this device.

Table 1: median hs-cTnI values in healthy subject, % of subjects above LoD (limit of detection) and %CV at 99th URL.