Myocardial infarction redefined: the new ACC/ESC definition, based on cardiac troponin, increases the apparent incidence of infarction.
OBJECTIVE
To investigate the impact of the redefinition of the diagnostic criteria for myocardial infarction on its apparent incidence in a non-selected and representative series of patients admitted with acute chest pain.


METHODS
Single centre prospective study.


METHODS
Medical assessment unit and cardiology wards of an inner city university hospital.


METHODS
80 consecutive patients aged over 25 years admitted with suspected ischaemic acute chest pain (excluding those where the ECG indicated definite myocardial infarction).


METHODS
Measurement of concentrations of conventional cardiac biomarkers (creatine kinase and its MB isoenzyme, CK-MB) and concentrations of the highly specific diagnostic indicator of myocardial damage, cardiac troponin I (cTnI) 12-24 hours after the onset of acute chest pain.


METHODS
Frequency of myocardial infarction as assessed by conventional diagnostic criteria (creatine kinase and CK-MB) plus clinical symptoms of infarction, versus frequency of infarction based on high sensitivity troponin assays.


RESULTS
Among patients with acute coronary syndromes but non-diagnostic ECG changes, 40% (32/80) fulfilled the new criteria for myocardial infarction using high sensitivity cTnI measurement, compared with 29% (23/80) using the conventional diagnostic criteria for myocardial infarction.


CONCLUSIONS
The implications of the redefinition of myocardial infarction on patients, their care, and the use of health care resources are substantial.
Ferguson
J L
JL
Department of Cardiology, The Royal Infirmary of Edinburgh, Lauriston Place, Edinburgh, UK.
Beckett
G J
GJ
Stoddart
M
M
Walker
S W
SW
Fox
K A A
KA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D052279:Creatine Kinase, MB Form; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014336:Troponin / Q000097:blood*
D015415:Biomarkers; D007527:Isoenzymes; D014336:Troponin; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form