Admission N-terminal pro-brain natriuretic peptide and its interaction with admission troponin T and ST segment resolution for early risk stratification in ST elevation myocardial infarction.
OBJECTIVE
To assess the long term prognostic value of N-terminal pro-brain natriuretic peptide (NT-proBNP) on admission and its prognostic interaction with both admission troponin T (TnT) concentrations and resolution of ST segment elevation in fibrinolytic treated ST elevation myocardial infarction (STEMI).


METHODS
Substudy of the ASSENT (assessment of the safety and efficacy of a new thrombolytic) -2 and ASSENT-PLUS trials.


METHODS
NT-proBNP and TnT concentrations were determined on admission in 782 patients. According to NT-proBNP concentrations, patients were divided into three groups: normal concentration (for patients < or = 65 years, < or = 184 ng/l and < or = 268 ng/l and for those > 65 years, < or = 269 ng/l and < or = 391 ng/l in men and women, respectively); higher than normal but less than the median concentration (742 ng/l); and above the median concentration. For TnT, a cut off of 0.1 microg/l was used. Of the 782 patients, 456 had ST segment resolution (< 50% or > or = 50%) at 60 minutes calculated from ST monitoring.


METHODS
All cause one year mortality.


RESULTS
One year mortality increased stepwise according to increasing concentrations of NT-proBNP (3.4%, 6.5%, and 23.5%, respectively, p < 0.001). In receiver operating characteristic analysis, NT-proBNP strongly trended to be associated more with mortality than TnT and time to 50% ST resolution (area under the curve 0.81, 95% confidence interval (CI) 0.72 to 0.9, 0.67, 95% CI 0.56 to 0.79, and 0.66, 95% CI 0.56 to 0.77, respectively). In a multivariable analysis adjusted for baseline risk factors and TnT, both raised NT-proBNP and ST resolution < 50% were independently associated with higher one year mortality, whereas raised TnT contributed independently only before information on ST resolution was added to the model.


CONCLUSIONS
Admission NT-proBNP is a strong independent predictor of mortality and gives, together with 50% ST resolution at 60 minutes, important prognostic information even after adjustment for TnT and baseline characteristics in STEMI.
Björklund
E
E
Department of Cardiology, University Hospital of Uppsala, Uppsala, Sweden. erik.bjorklund@akademiska.se
Jernberg
T
T
Johanson
P
P
Venge
P
P
Dellborg
M
M
Wallentin
L
L
Lindahl
B
B
D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000401:mortality; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010343:Patient Admission; D010446:Peptide Fragments / Q000097:blood*; D011379:Prognosis; D012044:Regression Analysis; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D020107:Troponin T / Q000097:blood*
D010446:Peptide Fragments; D020107:Troponin T; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain