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-care testing devices for monitoring cardiac markers to aid clinicians in ruling in and ruling out myocardial infarction (MI) is necessary for both laboratory and clinical acceptance.


METHODS
This study evaluated the clinical diagnostic sensitivity and specificity of the First Medical Cardiac Test device operated by nursing and laboratory personnel that simultaneously measures cardiac troponin I (cTnI), creatine kinase (CK) MB, myoglobin, and total CK on the Alpha Dx analyzer in whole blood for detection of MI. Over a 6-month period, 369 patients initially presenting to the emergency department with chest pain were evaluated for MI using modified WHO criteria. Eighty-nine patients (24%) were diagnosed with MI.


RESULTS
In whole blood samples collected at admission and at 3- to 6-h intervals over 24 h, ROC curve-determined MI decision limits were as follows: cTnI, 0.4 microgram/L; CKMB, 7.0 microgram/L; myoglobin, 180 microgram/L; total CK, 190 microgram/L. Based on peak concentrations within 24 h after presentation, the following 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-segment 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 hospital settings for ruling in and ruling out MI.
Apple
F S
FS
Hennepin County Medical Center, Department of Laboratory Medicine and Pathology, Minneapolis, MN 55415, USA. fred.apple@co.hennepin.mn.us
Anderson
F P
FP
Collinson
P
P
Jesse
R L
RL
Kontos
M C
MC
Levitt
M A
MA
Miller
E A
EA
Murakami
M M
MM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D052279:Creatine Kinase, MB Form; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D009211:Myoglobin / Q000097:blood; D019095:Point-of-Care Systems; D012372:ROC Curve; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood
D015415:Biomarkers; D007527:Isoenzymes; D009211:Myoglobin; D011933:Reagent Kits, Diagnostic; D019210:Troponin I; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form