title: A preliminary study of the utility of combined cardiac markers in the evaluation of patients presenting early with suspected acute coronary syndrome.
abstract: 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.
authors.affiliation: Department of Cardiology, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433.
authors.forename: J
authors.initials: J
authors.lastname: Lim
authors.forename: R C
authors.initials: RC
authors.lastname: Hawkins
authors.forename: K
authors.initials: K
authors.lastname: Ng
authors.forename: S P
authors.initials: SP
authors.lastname: Chan
authors.forename: A
authors.initials: A
authors.lastname: Cheng
authors.forename: K S
authors.initials: KS
authors.lastname: Ng
mesh_terms: 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*
chemical_list: D015415:Biomarkers; D007527:Isoenzymes; D020107:Troponin T; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form