An independent analytical verification found that a point-of-care high-sensitivity troponin I assay met manufacturer performance claims, demonstrating acceptable precision, minimal analytical interference, and strong concordance with laboratory-based assays across clinically relevant thresholds.
The researchers of the multicenter study evaluated the QuidelOrtho TriageTrue point-of-care (POC) high-sensitivity troponin I (hs-TnI) assay using whole blood and plasma samples from patients undergoing assessment for possible myocardial infarction. The study aimed to verify the assay's analytical performance and concordance with other assays and to verify secondary POC devices.
Methods
The researchers assessed intra-assay precision using five whole blood samples spanning the measuring interval, with up to 20 repeat measurements per sample. Inter-analyzer precision was evaluated across four analyzers, and inter-lot precision across two reagent lots over multiple days. Hemolysis interference was tested by spiking eight samples to hemolysis index levels up to 40 g/L.
The researchers assessed concordance in more than 200 samples between the TriageTrue sample, one other hs-TnI POC and four laboratory analyzers using the Pearson correlation and kappa statistics at the limit of quantitation and upper reference limit. Paired measurements from nine samples between a primary verified device and eight secondary devices were compared against prespecified difference limits, the researchers noted.
Key Findings
According to the researchers, intra-assay precision CVs were 25% and 12.2% at mean concentrations of 2.4 ng/L and 8.5 ng/L, respectively, and ranged from 2.8% to 15.9% at higher concentrations greater than 10 ng/L. Hemolysis caused minimal interference up to 10 g/L, exceeding the manufacturer's claim of 1.96 g/L.
Correlation coefficients ranged from 0.89 to 0.99 with other assays, except for the Roche hs-TnT assay (0.79), and were comparable to the laboratory assays. Of 116 comparisons with eight secondary analyzers, all met acceptable limits, the researchers noted.
Limitations
The study's researchers also noted that the logistical constraints in obtaining suitable whole blood EDTA samples and analyzing these within recommended timeframes limited targeted sampling at specific levels of cardiac troponin I precisely. The hs-TnI assay performed on the TriageTrue is deemed to perform adequately for the intended use in clinical settings and can be incorporated into clinical pathways, according to the researchers.
Conclusion
The researchers concluded that the assay's analytical performance supports its use in intended medical settings, including emergency care and rural/low-resource settings. As the researchers wrote, "Our verification studies support the performance characteristics of the TriageTrue assay as reported in the package insert."
Disclosures can be found in the study.
