Multicentre evaluation of the diagnostic value of cardiac troponin T, CK-MB mass, and myoglobin for assessing patients with suspected acute coronary syndromes in routine clinical practice.
OBJECTIVE
To assess the diagnostic efficiency of the third generation cardiac troponin T assay in routine clinical practice.


METHODS
Prospective observational study of unselected consecutive admissions.


METHODS
Multicentre study in 43 teaching and non-teaching hospitals in 13 countries.


METHODS
1105 hospital admissions, median age 67 years (range 15-96 years, 63.7% male) with suspected acute coronary syndromes (72.3% of cases) or other non-specific symptoms where cardiac disease required exclusion (27.7%).


METHODS
Over the study period, myoglobin, creatine kinase MB isoenzyme (CK-MB), and cardiac troponin T where measured in parallel with conventional diagnostic tests. Final diagnostic classification involved standard ECG changes and CK-MB mass exceeding 5.0 microg/l.


METHODS
Diagnostic efficiency was assessed by receiver operator characteristic curve analysis including and excluding patients with unstable angina.


RESULTS
Measurement of cardiac troponin T was diagnostically equivalent to CK-MB and both were better than myoglobin, with areas under the curve at 12 hours of 0.94, 0.99, and 0.80, respectively. Diagnostic criteria using CK-MB were inadequate and showed bias when patients with unstable angina were included. Elevations of cardiac troponin T did not occur when cardiac disease could be categorically excluded but were found in clinical conditions other than suspected acute coronary syndromes.


CONCLUSIONS
CK-MB is unsuitable as a diagnostic gold standard even at the proposed lower threshold. A lower cut off for cardiac troponin T of 0.05 microg/l should be used for diagnosis of acute myocardial infarction. Diagnosis of acute myocardial infarction cannot be made solely on the basis of a cardiac troponin T result.
Collinson
P O
PO
Department of Chemical Pathology, St George's Hospital, London, UK. paul.collinson@stgeorges.nhs.uk
Stubbs
P J
PJ
Kessler
A-C
AC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000097:blood / Q000175:diagnosis*; D002303:Cardiac Output, Low / Q000097:blood / Q000175:diagnosis; D003402:Creatine Kinase / Q000097:blood*; D052279:Creatine Kinase, MB Form; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000097:blood; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D017202:Myocardial Ischemia / Q000097:blood / Q000175:diagnosis; D009211:Myoglobin / Q000097:blood*; D011446:Prospective Studies; D012372:ROC Curve; D012206:Rhabdomyolysis / Q000097:blood; D013577:Syndrome; D020107:Troponin T / Q000097:blood*
D007527:Isoenzymes; D009211:Myoglobin; D020107:Troponin T; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form