Myoglobin, creatine kinase MB isoforms and creatine kinase MB mass in early diagnosis of myocardial infarction in patients with acute chest pain.
OBJECTIVE
Measurements of myoglobin and creatine kinase (CK)-MB isoforms have been suggested to be sensitive tests for the early diagnosis of myocardial infarction (MI). We have investigated the utility of myoglobin, creatine kinase (CK)-MB isoforms and creatine kinase MB mass (CK-MBm) in early diagnosis of MI using cardiac troponin T (cTnT) positivity as a reference.


METHODS
The study population comprised 440 patients who had had chest pain for less than 12 h. Patients were divided into cTnT negative (cTnT-) or cTnT positive (cTnT+) patients (concentration of cTnT >0.1 microg/L at two different time points during 72 h).


RESULTS
At the time of admission to the emergency department receiver operating characteristics (ROC) curves of CK-MB isoforms and CK-MBm were not better than that of myoglobin. Six hours after admission CK-MB isoforms and CK-MBm provided statistically significantly larger areas under the curve (AUC) than myoglobin (p < 0.01). When ROC curves were related to the onset of chest pain (< 3 h, 3-6 h, and > 6 h) there were no significant differences between the cardiac markers studied.


CONCLUSIONS
According to the present findings, CK-MB isoforms or myoglobin offer no advantage over CK-MBm as early markers of myocardial infarction.
Penttilä
Karri
K
Department of Clinical Chemistry, Kuopio University Hospital, Kuopio, Finland. karri.penttila@kuh.fi
Koukkunen
Heli
H
Halinen
Matti
M
Rantanen
Tapio
T
Pyörälä
Kalevi
K
Punnonen
Kari
K
Penttilä
Ilkka
I
D000368:Aged; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood*; D052279:Creatine Kinase, MB Form; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D008297:Male; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D009211:Myoglobin / Q000097:blood*; D020033:Protein Isoforms; D012372:ROC Curve; D020107:Troponin T / Q000097:blood
D015415:Biomarkers; D007527:Isoenzymes; D009211:Myoglobin; D020033:Protein Isoforms; D020107:Troponin T; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form