The potential utility of a rapid CK-MB assay in evaluating emergency department patients with possible myocardial infarction.
OBJECTIVE
To determine the sensitivity, specificity, and predictive values of a new rapid creatine kinase-MB (R-CK-MB) assay compared with a standard CK-MB (S-CK-MB) assay and to determine its potential use in the evaluation of emergency department patients with possible myocardial infarction.


METHODS
Retrospective patient identification with subsequent testing of excess sera for CK-MB and total CK using an identity-unlinked procedure.


METHODS
Large, urban, teaching hospital ED.


METHODS
All adult patients with excess sera and one of several defined presentations chosen to identify those with possible myocardial ischemia or infarction. Patients with clearly documented noncardiac etiologies of their symptoms or signs were excluded.


RESULTS
The sensitivity, specificity, and positive and negative predictive values of 271 patient specimens for the R-CK-MB assay compared with the S-CK-MB assay were 100%, 96.8%, 75.0%, and 100%, respectively. The R-CK-MB assay was positive for 32 patients (11.8%). Of these, eight (25.0%) were admitted to unmonitored beds, and five (15.6%) were discharged home. All of these 13 patients had initial ECGs without evidence of ischemia or infarction. On follow-up, at least eight of the 13 had evidence of infarction.


CONCLUSIONS
The R-CK-MB assay demonstrated high sensitivity and specificity compared with the S-CK-MB assay. When used for patients in whom a cardiac care unit admission is not considered, the rapid assay may identify some patients with unsuspected myocardial infarction and prevent inadvertent discharge or admission to unmonitored beds.
Green
G B
GB
Division of Emergency Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Hansen
K N
KN
Chan
D W
DW
Guerci
A D
AD
Fleetwood
D H
DH
Sivertson
K T
KT
Kelen
G D
GD
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015142:Baltimore / Q000453:epidemiology; D003402:Creatine Kinase / Q000097:blood*; D004562:Electrocardiography; D004636:Emergency Service, Hospital; D005069:Evaluation Studies as Topic; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D007118:Immunoassay / Q000592:standards*; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000592:standards*; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D015995:Prevalence; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors
D003402:Creatine Kinase