A sensitive cardiac troponin T assay in stable coronary artery disease.
BACKGROUND
In most patients with stable coronary artery disease, plasma cardiac troponin T levels are below the limit of detection for the conventional assay. The distribution and determinants of very low circulating troponin T levels, as well as their association with cardiovascular events, in such patients are unknown.


METHODS
We used a new, high-sensitivity assay to determine the concentration of cardiac troponin T in plasma samples from 3679 patients with stable coronary artery disease and preserved left ventricular function. Results of the assay were analyzed in relation to the incidence of cardiovascular events during a median follow-up period of 5.2 years.


RESULTS
With the highly sensitive assay, concentrations of cardiac troponin T were at or above the limit of detection (0.001 microg per liter) in 3593 patients (97.7%) and at or above the 99th percentile for apparently healthy subjects (0.0133 microg per liter) in 407 patients (11.1%). After adjustment for other independent prognostic indicators, there was a strong and graded increase in the cumulative incidence of cardiovascular death (adjusted hazard ratio per unit increase in the natural logarithm of the troponin T level, 2.09; 95% confidence interval [CI], 1.60 to 2.74; P<0.001) and of heart failure (adjusted hazard ratio, 2.20; 95% CI, 1.66 to 2.90; P<0.001) in this study group. Increased risk associated with higher levels of troponin T was evident well below the limit of detection of conventional cardiac troponin T assays and below the 99th percentile of values in a healthy population. There was no association between troponin T levels as measured with the highly sensitive assay and the incidence of myocardial infarction (adjusted hazard ratio, 1.16; 95% CI, 0.97 to 1.40; P=0.11).


CONCLUSIONS
After adjustment for other independent prognostic indicators, cardiac troponin T concentrations as measured with a highly sensitive assay were significantly associated with the incidence of cardiovascular death and heart failure but not with myocardial infarction in patients with stable coronary artery disease.
Omland
Torbjørn
T
Division of Medicine, Akershus University Hospital, Lørenskog, Norway. torbjorn.omland@medisin.uio.no
de Lemos
James A
JA
Sabatine
Marc S
MS
Christophi
Costas A
CA
Rice
Madeline Murguia
MM
Jablonski
Kathleen A
KA
Tjora
Solve
S
Domanski
Michael J
MJ
Gersh
Bernard J
BJ
Rouleau
Jean L
JL
Pfeffer
Marc A
MA
Braunwald
Eugene
E
D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000401:mortality; D003324:Coronary Artery Disease / Q000097:blood / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000453:epidemiology / Q000401:mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology / Q000401:mortality; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic; D012680:Sensitivity and Specificity; D020107:Troponin T / Q000097:blood*; D016277:Ventricular Function, Left
D015415:Biomarkers; D020107:Troponin T