Ruling out myocardial infarction with troponin T and creatine kinase MB mass: diagnostic and prognostic aspects.
OBJECTIVE
To investigate the time window for ruling out myocardial infarction (MI) with troponin T (TnT) and creatine kinase isoenzyme MB mass (CK-MBm) and the prognosis of patients with ruled-out MI diagnosis.


METHODS
The study was based on 397 patients admitted with a suspected acute coronary syndrome but with relief of symptoms within 24 h.


RESULTS
MI diagnosis was confirmed with elevated TnT (>0.10 microg/l) in 108 patients. in 91% within 12-24 h from the onset of symptoms, and in 99% within 12 h from admission. In 94 of these patients CK-MBm became elevated (>5.0 microg/l). in 95% within 10-12 h from the onset of symptoms, and in 99% within 6 h from admission. Among patients with ruled-out MI diagnosis, the 1-year incidence of recurrent coronary events was 29% in those with positive history of coronary heart disease (CHD) but only 7% in those without prior CHD (p < 0.001).


CONCLUSIONS
Using TnT or CK-MBm, MI can be ruled out within 12 h from admission in the majority of patients. Among patients with ruled-out MI diagnosis, positive history of CHD is an important determinant of prognosis.
Koukkunen
H
H
Department of Medicine, Kuopio University Hospital, Finland.
Penttilä
K
K
Kemppainen
A
A
Penttilä
I
I
Halinen
M
M
Rantanen
T
T
Pyörälä
K
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003327:Coronary Disease / Q000175:diagnosis; D003402:Creatine Kinase / Q000097:blood*; D052279:Creatine Kinase, MB Form; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D011379:Prognosis; D012680:Sensitivity and Specificity; D020107:Troponin T / Q000097:blood*
D015415:Biomarkers; D007527:Isoenzymes; D020107:Troponin T; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form