The value of NT-proBNP in early risk stratification of acute coronary syndromes.
BACKGROUND
The N-terminal portion of brain natriuretic peptide (NT-proBNP) has been identified as an indicator of prognosis in different cardiovascular diseases. Its role in risk stratification in patients with acute coronary syndromes (ACS) is still under evaluation.


OBJECTIVE
We aimed to evaluate the prognostic value of NT-proBNP measured in the first 48 hours after admission due to an acute coronary syndrome.


METHODS
Our study included 142 patients (aged 62.7 +/- 12.0 years, 70.4% males) admitted to a cardiology unit with an ACS. All laboratory evaluations were performed in the first 48 hours after admission. The mean follow-up was 200 days. Death from any cause or hospitalization because of a major acute cardiovascular event (whichever occurred first) was defined as the end-point.


RESULTS
Cardiovascular risk factors were found in a significant proportion of our sample (hypertension in 56.3%, diabetes mellitus in 38.0%, current or previous smoking in 51.4%, dyslipidemia in 67.6%). Fifty-eight patients had left ventricular systolic dysfunction (LVSD). Serum levels of NT-proBNP were 2174 +/- 4801 pg/ml. Variables associated with event-free survival in univariate analysis were: NT-proBNP (HR 1.007, 95% CI 1.003-1.011, for each 100 pg/ml increment), serum glucose (hazard ratio [HR] 1.007, 95% CI 1.001-1.012, for each 1 mg/dl increment) and maximum cardiac troponin I (cTnI) level (HR 1.005, 95% CI 1.001-1.009, for each 1 ng/ml increment). The white blood count (WBC) was marginally associated with a poor prognosis (HR 1.152, 95% CI 0.994-1.335, for each 1000/mm3 increment). After adjustment for the above variables, age, sex, left ventricular systolic dysfunction, diabetes, coronary anatomy and coronary revascularization using a forward likelihood ratio Cox regression model, NT-proBNP remained the only variable with significant prognostic value (HR 1.007, 95% CI 1.003-1.011, for each 100 pg/ml increment).


CONCLUSIONS
These data suggest that NT-proBNP is a strong clinical predictor of prognosis in acute coronary syndromes. Its early measurement should be included in the risk stratification strategy in this setting.
Almeida
Rui
R
Department of Cardiology, Hospital de São João, Porto, Portugal. ruialmeida@netcabo.pt
Mariano
Luís
L
Gavina
Cristina
C
Pinho
Teresa
T
Vasconcelos
Mariana
M
Ferreira
António
A
Maciel
M Júlia
MJ
Gonçalves
F Rocha
FR
D000208:Acute Disease; D000789:Angina, Unstable / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D013577:Syndrome; D013997:Time Factors
D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain