BACKGROUND: The association between plasma levels of N-terminal pro-brain 
natriuretic peptide (NT-proBNP) and prognostic outcomes in patients after 
ischemic stroke remains unknown. The present study tested the hypothesis that 
NT-proBNP level is noticeably increased after ischemic stroke and that elevated 
NT-proBNP is associated with unfavorable clinical outcomes (UFCO).
METHODS AND RESULTS: Blood samples for NT-proBNP levels were collected serially 
and examined with sandwich immunoassay after acute ischemic stroke in 86 
consecutive patients. The NT-proBNP levels were also measured in 30 healthy 
control volunteers and 30 at-risk control subjects. The NT-proBNP levels were 
significantly higher at 4 intervals after ischemic stroke than in healthy and 
at-risk control subjects (all p<0.001). The NT-proBNP decreased to a 
significantly lower level on day 21 and to a substantially lower level on day 
90. Additionally, the NT-proBNP level at any of the 4 intervals was 
significantly higher in patients with than in patients without UFCO (defined as 
combined congestive heart failure > or = class 3, acute myocardial infarction, 
recurrent stroke or any cause of death) (all p<0.01). Multivariate analysis 
demonstrated that age and NIH Stroke Scale were the 2 strongest independent 
predictors of increased NT-proBNP levels (all p<0.01). Furthermore, increased 
NT-proBNP (> or = 150 pg/ml) was the strongest independent predictor of 
long-term (mean follow-up: 24 months) UFCO (26 patients) (all p<0.05).
CONCLUSIONS: The NT-proBNP level was markedly elevated after acute ischemic 
stroke and declined substantially thereafter. An increased NT-proBNP level was 
strongly and independently correlated with UFCO in patients after ischemic 
stroke.