title: Elevated BNP is associated with vasospasm-independent cerebral infarction following aneurysmal subarachnoid hemorrhage.
abstract: BACKGROUND
  Elevated levels of B-type natriuretic peptide (BNP) have been associated with cardiac dysfunction and adverse neurological outcomes after subarachnoid hemorrhage (SAH). We sought to determine whether elevated levels of BNP are independently associated with radiographic cerebral infarction after SAH.
  
  
  METHODS
  Plasma BNP levels were measured after admission, a mean of 5.5 ± 3.0 days after SAH onset. Cerebral infarction was determined by retrospective review of computerized tomography (CT) scans. Cerebral vasospasm was confirmed by the presence of vascular narrowing on cerebral angiogram. The association between BNP and cerebral infarction was quantified using multivariable logistic regression and reverse stepwise elimination of clinical covariates. A stratified analysis was performed to quantify the association between BNP levels and infarction in patients with and without angiographic vasospasm.
  
  
  RESULTS
  BNP levels were measured from 119 subjects. The median BNP level was 105 pg/ml (interquartile range 37-275 pg/ml). In our multivariable model, the top quartile of BNP levels (≥ 276 pg/ml) were associated with an increased odds of cerebral infarction (OR 4.2, P = 0.009). The stratified analysis showed that the association between BNP and infarction was strongest in patients without angiographic vasospasm (OR 7.8, P = 0.006).
  
  
  CONCLUSIONS
  Elevated levels of BNP are strongly and independently associated with cerebral infarction, and the association is most pronounced in patients without angiographic vasospasm. These results provide further evidence that other mechanisms can contribute to infarction, and BNP may be a useful biomarker in detecting patients at risk for adverse outcomes without large vessel vasospasm.
authors.affiliation: Department of Medicine, Cardiology Division, University of California, San Diego, CA 94114, USA.
authors.forename: Pam R
authors.initials: PR
authors.lastname: Taub
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Fields
authors.forename: Alan H B
authors.initials: AH
authors.lastname: Wu
authors.forename: Jacob C
authors.initials: JC
authors.lastname: Miss
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lawton
authors.forename: Wade S
authors.initials: WS
authors.lastname: Smith
authors.forename: William L
authors.initials: WL
authors.lastname: Young
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Zaroff
authors.forename: Nerissa U
authors.initials: NU
authors.lastname: Ko
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002544:Cerebral Infarction / Q000097:blood* / Q000000981:diagnostic imaging* / Q000209:etiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D013345:Subarachnoid Hemorrhage / Q000097:blood* / Q000150:complications / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D020301:Vasospasm, Intracranial / Q000097:blood* / Q000000981:diagnostic imaging / Q000209:etiology
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain