Evaluation of cardiac troponin I stability in blood sample using the AccuTnI+3 assay.

OBJECTIVE

Troponins are considered as the biomarkers of choice to highlight cardiac injury in emergency departments, but are also valuable to detect cardiac injury in a non-emergency setting. In this latter case, transport of blood samples to laboratories often exceeds the manufacturer's recommendations (<2 h between vein puncture and analysis for the Beckman Coulter AccuTnI+3 assay). We aim to evaluate in vitro the stability of troponin Ic (cTnI) at two intervals (<2 h and at 4 h) over a wide range of concentrations using the Beckman Coulter AccuTnI+3 assay.

PATIENTS AND METHODS

For each of the 95 patients included in this study, we analyzed the first blood sample with a time of transport <2 h, and the second sample after 4 h from vein puncture. We then calculated the correlation between the two periods of analysis and evaluated the bias by a Bland-Altman test.

RESULTS

Taking into account of our analytical reproducibility, we did not observe any significant differences in cTnI values between <2 h and 4 h.

CONCLUSIONS

The time between vein puncture and analysis of cTnI can be extended to 4 h.