Two Point-of-Care Cardiac Troponin I Immunoassays Have Acceptable Analytical Performance for the Detection of Measurands of Cardiac Troponin I Cardiac Muscle Homogenates From Southern-Central Black Rhinoceros (Diceros bicornis minor) and Southern White Rhinoceros (Ceratotherium simum simum).

Abstract

Background: Skeletal and possible cardiac muscle damage has been reported in chemically immobilized and transported African rhinoceros during conservation-related activities. The extent of cardiac muscle injury in these rhinoceros is unknown due to a lack of validated cardiac troponin I (cTnI) assays. However, recently, five human cTnI assays were deemed suitable for analytical validation in African rhinoceros based on cTnI sequencing results.

Objectives: The first objective was to validate two cTnI immunoassay point-of-care analyzers (POCAs) in African rhinoceros and, secondly, to perform quality control (QC) validation for the POCAs.

Methods: Analytical validation of the Stratus CS Acute Care Troponin I cTnI immunoassay and Atellica VTLi high sensitivity cTnI (hs-cTnI) assay was performed using rhinoceros serum samples and species-specific cardiac muscle homogenate. Experiments included precision studies, reportable range, hemoglobin interference studies, recovery studies, and detection limit studies, with results assessed against prescribed total allowable error (TE_a) performance goals. Commercial quality control material (QCM) data were used to calculate bias and imprecision for QC validation.

Results: Imprecision was acceptable (1.9%-10.3%) and met low cTnI concentration performance goals. Reportable ranges were similar to the manufacturer's specifications. High hemoglobin concentrations in white rhinoceros resulted in a positive bias in the Stratus CS. A simple 1_3s QC rule using two levels of QCM and a TEa of 70% could be used in both analyzers, except at very low cTnI concentrations in the Atellica VTLi.

Conclusions: Both cTnI POCAs are suitable for use in African rhinoceros, and analytical performance goals for low cTnI concentrations in hs-cTnI assays were met.