title: B-type natriuretic peptides and mortality after stroke: a systematic review and meta-analysis.
abstract: OBJECTIVE
  To measure the association of B-type natriuretic peptide (BNP) and N-terminal fragment of BNP (NT-proBNP) with all-cause mortality after stroke, and to evaluate the additional predictive value of BNP/NT-proBNP over clinical information.
  
  
  METHODS
  Suitable studies for meta-analysis were found by searching MEDLINE and EMBASE databases until October 26, 2012. Weighted mean differences measured effect size; meta-regression and publication bias were assessed. Individual participant data were used to estimate effects by logistic regression and to evaluate BNP/NT-proBNP additional predictive value by area under the receiver operating characteristic curves, and integrated discrimination improvement and categorical net reclassification improvement indexes.
  
  
  RESULTS
  Literature-based meta-analysis included 3,498 stroke patients from 16 studies and revealed that BNP/NT-proBNP levels were 255.78 pg/mL (95% confidence interval [CI] 105.10-406.47, p = 0.001) higher in patients who died; publication bias entailed the loss of this association. Individual participant data analysis comprised 2,258 stroke patients. After normalization of the data, patients in the highest quartile had double the risk of death after adjustment for clinical variables (NIH Stroke Scale score, age, sex) (odds ratio 2.30, 95% CI 1.32-4.01 for BNP; and odds ratio 2.63, 95% CI 1.75-3.94 for NT-proBNP). Only NT-proBNP showed a slight added value to clinical prognostic variables, increasing discrimination by 0.028 points (integrated discrimination improvement index; p < 0.001) and reclassifying 8.1% of patients into correct risk mortality categories (net reclassification improvement index; p = 0.003). Neither etiology nor time from onset to death affected the association of BNP/NT-proBNP with mortality.
  
  
  CONCLUSIONS
  BNPs are associated with poststroke mortality independent of NIH Stroke Scale score, age, and sex. However, their translation to clinical practice seems difficult because BNP/NT-proBNP add only minor predictive value to clinical information.
authors.affiliation: From the Neurovascular Research Laboratory (T.G.-B., D.G., A.B., J.M.), Vall d'Hebron Institute of Research, Universitat Autònoma de Barcelona, Spain; Department of Neurology (T.E.), Kliniken Südostbayern-Klinikum Traunstein, Germany; Department of Psychiatry and Psychotherapy (T.E.), Technische Universität München, Germany; Department of Cardiology (J.K.J.), Odense University, Denmark; Stroke Medicine (J.C.S.), Lincoln County Hospital, University of Nottingham, UK; Department of Stroke Medicine (K.S.), Kawasaki Medical School, Kurashiki City, Okayama, Japan; Department of Emergency Medicine (A.S.), School of Medicine, Duzce University, Turkey; Department of Neurology (X.C.), Fujian Provincial Hospital, Fujian Medical University, Fuzhou, China; and Centre for Clinical Brain Sciences (W.N.W.), University of Edinburgh, UK.
authors.forename: Teresa
authors.initials: T
authors.lastname: García-Berrocoso
authors.forename: Dolors
authors.initials: D
authors.lastname: Giralt
authors.forename: Alejandro
authors.initials: A
authors.lastname: Bustamante
authors.forename: Thorleif
authors.initials: T
authors.lastname: Etgen
authors.forename: Jesper K
authors.initials: JK
authors.lastname: Jensen
authors.forename: Jagdish C
authors.initials: JC
authors.lastname: Sharma
authors.forename: Kensaku
authors.initials: K
authors.lastname: Shibazaki
authors.forename: Ayhan
authors.initials: A
authors.lastname: Saritas
authors.forename: Xingyong
authors.initials: X
authors.lastname: Chen
authors.forename: William N
authors.initials: WN
authors.lastname: Whiteley
authors.forename: Joan
authors.initials: J
authors.lastname: Montaner
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D006801:Humans; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D020521:Stroke / Q000097:blood* / Q000175:diagnosis / Q000401:mortality*
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain