Traditionally, troponin levels are measured in the blood using an automated laboratory protocol, but the use of a faster technology, the point-of-care (POC) testing of troponin levels, has shown promise in the effective differential diagnosis of cardiac injury. The purpose of this study was to compare the 2 methods. A total of 1567 patients were seen in the emergency department who were tested with both the POC iSTAT troponin and laboratory troponin from a secondary analysis of retrospective data collected between June 2012 and December 2012. The values for laboratory troponin varied between 0 and 30 with a mean and standard deviation of 0.060 ± 0.842 and the values for POC testing varied between 0 and 17.2 with a mean and standard deviation of 0.042 ± 0.492. The Bland-Altman analysis showed a systematic negative bias for the POC values compared with the laboratory troponin values. Lowering the POC cut-off value for troponin to 0.035 yielded 3 out of 4 better validity coefficients compared with those with the suggested manufacturer's cut-off value of 0.08 when predicting the gold standard. The POC troponin can be used to measure troponin level and similar diagnosis if the cut-off value for the POC troponin is lowered to 0.035 instead of the 0.08 suggested manufacturer's cut-off.
West Kendall Baptist Hospital, Miami, Florida (Ms Sardi, Dr Lamoureux, and Ms Phillip-Samuel); and Nursing and Health Sciences Research, Baptist Health South Florida, Miami, Florida, and Boston, Massachusetts (Dr Cohn).
Correspondence: Adacilis Ramirez Sardi, BS, MT (ASCP), Transfusion Services, West Kendall Baptist Hospital, 9555 SW 162 Ave, Miami, FL (adacilisR@baptisthealth.net).
The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article.