Clinical evaluation of the first medical whole blood, point-of-care testing device for detection of myocardial infarction

Background: Validation of whole blood, point-of-rare testing devices for mo nitoring cardiac markers to aid clinicians in ruling in and ruling out myoc ardial infarction (MI) is necessary for both laboratory and clinical accept ance. Methods: This study evaluated the clinical diagnostic sensitivity and speci ficity of the First Medical Cardiac Test device operated by nursing and lab oratory personnel that simultaneously measures cardiac troponin I (cTnI), c reatine kinase (CK) MB, myoglobin, and total CK on the Alpha Dr analyzer in whole blood for detection of MI. Over a 6-month period, 369 patients initi ally presenting to the emergency department with chest pain were evaluated for MI using modified WHO criteria. Eighty-nine patients (24%) were diagnos ed with MI. Results: In whole blood samples collected at admission and at 3- to 6-h int ervals over 24 h, ROC curve-determined MI decision limits were as follows: cTnI, 0.4 mu g/L; CKMB, 7.0 mu g/L; myoglobin, 180 mu g/L; total CK, 190 mu g/L. Based on peak concentrations within 24 h after presentation, the foll owing sensitivities (+/- 95% confidence intervals) were found: cTnI, 93% +/ - 5.5%; myoglobin, 81% +/- 9.7%; CKMB, 90% +/- 6.3%; total CK, 86% +/- 7.5% . Sensitivities were maximal at >90% for both cTnI and CKMB at >12 h in MI patients, without differences between ST-segment elevation and non-ST-segme nt elevation MI patients. Conclusions: The First Medical point-of-care device provides cardiac marker assays that can be used by laboratories and clinicians in a variety of hos pital settings for ruling in and ruling out MI. (C) 2000 American Associati on for Clinical Chemistry.