Classification and risk stratification of patients with acute chest pain using a low discriminatory level of cardiac troponin T.
BACKGROUND
Cardiac troponins are the biochemical markers of choice for the evaluation of acute coronary syndromes (ACS). Using the first-generation test, most studies related adverse outcome to > 0.20 or 0.10 microg/l cardiac troponin T (cTnT) levels. With the highly sensitive and specific second- and third-generation assays, cTnT is undetectable in most healthy individuals.


OBJECTIVE
We evaluated whether a lower cTnT level, within 24 h of admission, could indicate an increased risk of future complications.


METHODS
During 1998-1999, clinical data were collected in 260 patients with ACS. Cardiac troponin T was measured at arrival, and 4, 8, and 12-24 h thereafter. The maximum cTnT value was then used to assess, over a 15-month follow-up period, the cumulative risk of death or myocardial infarction (MI), as well as rates of events according to quartiles of cTnT values.


RESULTS
Patients with < or = 0.03 microg/l cTnT levels had the lowest rate of adverse events and the best Kaplan-Meier event-free survival curve. Increasing cTnT levels were associated with stepwise increases in mortality rates and with a constant 10-fold increase in MI rates during follow-up.


CONCLUSIONS
A low threshold cTnT elevation is recommended to assess the risk of ACS. All cTnT elevations > 0.03 microg/l predict a higher risk of MI during follow-up, whereas increasing values predict mortality in relation to the amount of elevation.
Solymoss
B Charles
BC
Department of Laboratory Medicine, Montreal Heart Institute, Montreal, Quebec, Canada. solymoss@icm.umontreal.ca
Bourassa
Martial G
MG
Cernacek
Peter
P
Fortier
Annik
A
Théroux
Pierre
P
D000208:Acute Disease; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002637:Chest Pain / Q000097:blood* / Q000145:classification*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D020107:Troponin T / Q000097:blood*
D015415:Biomarkers; D020107:Troponin T