title: The predictive ability of pre-operative B-type natriuretic peptide in vascular patients for major adverse cardiac events: an individual patient data meta-analysis.
abstract: OBJECTIVE
  The aims of this study were to perform an individual patient data meta-analysis of studies using B-type natriuretic peptides (BNPs) to predict the primary composite endpoint of cardiac death and nonfatal myocardial infarction (MI) within 30 days of vascular surgery and to determine: 1) the cut points for a natriuretic peptide (NP) diagnostic, optimal, and screening test; and 2) if pre-operative NPs improve the predictive accuracy of the revised cardiac risk index (RCRI).
  
  
  BACKGROUND
  NPs are independent predictors of cardiovascular events in noncardiac and vascular surgery. Their addition to clinical risk indexes may improve pre-operative risk stratification.
  
  
  METHODS
  Studies reporting the association of pre-operative NP concentrations and the primary study endpoint, post-operative major adverse cardiovascular events (defined as cardiovascular death and nonfatal MI) in vascular surgery, were identified by electronic database search. Secondary study endpoints included all-cause mortality, cardiac death, and nonfatal MI.
  
  
  RESULTS
  Six data sets were obtained, 5 for BNP (n = 632) and 1 for N-terminal pro-BNP (n = 218). An NP level higher than the optimal cut point was an independent predictor for the primary composite endpoint (odds ratio: 7.9; 95% confidence interval: 4.7 to 13.3). BNP cut points were 30 pg/ml for screening (95% sensitivity, 44% specificity), 116 pg/ml for optimal (highest accuracy point; 66% sensitivity, 82% specificity), and 372 pg/ml for diagnostic (32% sensitivity, 95% specificity). Subsequent to revised cardiac risk index stratification, reclassification using the optimal cut point significantly improved risk prediction in all groups (net reclassification improvement 58%, p < 0.000001), particularly in the intermediate-risk group (net reclassification improvement 84%, p < 0.001).
  
  
  CONCLUSIONS
  Pre-operative NP levels can be used to independently predict cardiovascular events in the first 30 days after vascular surgery and to significantly improve the predictive performance of the revised cardiac risk index.
authors.affiliation: Perioperative Research Unit, Department of Anaesthetics, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Congella, South Africa. reitzerodseth@gmail.com
authors.forename: Reitze N
authors.initials: RN
authors.lastname: Rodseth
authors.forename: Giovana A
authors.initials: GA
authors.lastname: Lurati Buse
authors.forename: Daniel
authors.initials: D
authors.lastname: Bolliger
authors.forename: Christoph S
authors.initials: CS
authors.lastname: Burkhart
authors.forename: Brian H
authors.initials: BH
authors.lastname: Cuthbertson
authors.forename: Simon C
authors.initials: SC
authors.lastname: Gibson
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Mahla
authors.forename: David W
authors.initials: DW
authors.lastname: Leibowitz
authors.forename: Bruce M
authors.initials: BM
authors.lastname: Biccard
mesh_terms: D002318:Cardiovascular Diseases / Q000401:mortality*; D006801:Humans; D009203:Myocardial Infarction / Q000453:epidemiology*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood; D057234:Preoperative Period; D012372:ROC Curve; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D014656:Vascular Surgical Procedures
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain