A preliminary study of the utility of combined cardiac markers in the evaluation of patients presenting early with suspected acute coronary syndrome.
OBJECTIVE
The aim of the study was to investigate and compare the usefulness and accuracy of various cardiac markers [troponin I, creatine kinase MB (CKMB) mass, creatine kinase (CK), CKMB activity] to aid early diagnosis of myocardial infarction. We also examined the ability of the various cardiac markers to prognosticate future adverse cardiac events.


METHODS
Patients admitted within 8 hours of maximal chest pain suggestive of acute coronary syndrome with non-diagnostic electrocardiograms were recruited. Blood samples were obtained on admission to the wards and repeated 4 hours later. These results were later correlated to the final hospital discharge diagnosis.


RESULTS
The 37 patients in the study were a high-risk population with over 50% presenting with a Thrombolysis in Myocardial Infarction (TIMI) risk score of greater or equal to 3. Myoglobin was the most sensitive marker (100% sensitivity) in early prediction of patients who were subsequently diagnosed to have a myocardial infarction. Patients with an elevated troponin I level but normal CK and myoglobin levels had a significantly higher risk of developing a major adverse clinical event (MACE) within 3 months of the initial presentation.


CONCLUSIONS
Myoglobin is the most sensitive marker when compared to CK, CKMB and troponin I for diagnosing patients presenting early with chest pain and a non-diagnostic electrocardiogram and who subsequently develop either a ST-elevation myocardial infarction or non-ST elevation myocardial infarction. Patients with an elevated troponin I level but normal CK and myoglobin levels are at higher risk of an adverse clinical event.
Lim
J
J
Department of Cardiology, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433.
Hawkins
R C
RC
Ng
K
K
Chan
S P
SP
Cheng
A
A
Ng
K S
KS
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000175:diagnosis* / Q000453:epidemiology; D015415:Biomarkers / Q000032:analysis; D003402:Creatine Kinase / Q000032:analysis / Q000378:metabolism*; D052279:Creatine Kinase, MB Form; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000032:analysis / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000453:epidemiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D012307:Risk Factors; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D017678:Sex Distribution; D012846:Singapore / Q000453:epidemiology; D013997:Time Factors; D020107:Troponin T / Q000032:analysis / Q000378:metabolism*
D015415:Biomarkers; D007527:Isoenzymes; D020107:Troponin T; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form