Diagnostic value of a point-of-care cardiac troponin-I assay (i-STAT®) for clinical application in canine and feline cardiology.

Abstract

INTRODUCTION/OBJECTIVES: This study was performed to evaluate the diagnostic value and net benefits, including cost-effectiveness, of a point-of-care analyser (i-STAT®) for measurement of cardiac troponin I (cTnI) in dogs and cats. ANIMALS, MATERIALS AND METHODS: Hundred and twenty dogs and 120 cats presented with signs of cardiac disease and suspected myocardial insult on cardiac assessment. This was a validation study expressed as agreement between the i-STAT® analyser and two common commercial reference methods (IMMULITE® 2000 and ACCESS® hsTnI). RESULTS: The comparison between methods showed a negative bias between the i-STAT® and the two commercial cTnI assays. The bias was more evident when the i-STAT® values were compared to the traditional cTnI assay (IMMULITE® 2000), with a calculated difference of -1.14 ng/mL (dogs) and -0.96 ng/mL (cats). However, the bias was distinctly lower when the i-STAT® measurements were compared to the high-sensitivity cTnI assay (ACCESS®), namely -0.3 ng/mL in dogs and -0.17 in cats. DISCUSSION: The i-STAT® method can reliably detect normal, low and elevated cTnI values, which is fundamental to differentiate pets with and without myocardial damage and, with the rapid availability of results, this confirms the clinical utility of the i-STAT® method. CONCLUSIONS: cardiac troponin I concentrations measured with the i-STAT® have good comparability with those obtained with both commercial assays for low and elevated cTnI values. However, results should be cautiously interpreted for high cTnI values, especially if a strict cut-off value is adopted for diagnostic or prognostic purposes in critical clinical conditions, such as myocarditis or acute myocardial ischaemia.