NT-proBNP levels in patients with non-ST-segment elevation acute coronary syndrome.
BACKGROUND
Non-ST-segment elevation acute coronary syndrome is associated with elevation of brain natriuretic peptide and markers of myocardial necrosis, although its relationship with the TIMI score and left ventricular function are largely unknown.


OBJECTIVE
To evaluate the correlation between plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) and markers of myocardial necrosis [creatine phosphokinase muscle-brain fraction (CK-MB) and troponin I], TIMI risk score and left ventricular ejection fraction in patients with non-ST-segment elevation acute coronary syndrome.


METHODS
Eighty-seven patients with non-ST-segment elevation acute coronary syndrome were divided into two groups: 37 (42.5%) with unstable angina and 50 (57.5%) with non-ST-segment elevation myocardial infarction.


RESULTS
Left ventricular ejection fraction more than 40% was found in 86.2% of the total sample. Serum levels of NT-proBNP was higher in patients with non-ST elevation myocardial infarction than in those with unstable angina (p<0.001). Increased levels of NT-proBNP were associated with increases in troponin I (rs=0.425, p<0.001), peak CK-MB (rs=0.458, p<0.001) and low left ventricular ejection fraction (rs=-0.345, p=0.002); no correlation was found with the TIMI risk score (rs=0.082, p=0.44). Multivariate analysis revealed that left ventricular ejection fraction and troponin I levels were independently correlated with NT-proBNP levels (p=0.017 and p=0.002, respectively).


CONCLUSIONS
Increased levels of NT-proBNP in patients with non-ST-segment elevation acute coronary syndrome are not related exclusively to low left ventricular ejection fraction, but can also be caused by the presence of myocardial ischemia and necrosis.
Hospital das Clínicas, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
Luiz Ricardo A
LR
Castro
Maria Clara N
MC
Alencar
Márcia M
MM
Barbosa
Maria do Carmo P
Mdo C
Nunes
José Ronaldo
JR
Cardoso
Antonio Luiz P
AL
Ribeiro
D054058:Acute Coronary Syndrome / Q000097:blood* / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D052279:Creatine Kinase, MB Form / Q000097:blood*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D009336:Necrosis; D010446:Peptide Fragments / Q000097:blood*; D018570:Risk Assessment; D013318:Stroke Volume / Q000502:physiology; D019210:Troponin I / Q000097:blood*
D015415:Biomarkers; D010446:Peptide Fragments; D019210:Troponin I; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D052279:Creatine Kinase, MB Form