title: Increased peak postoperative B-type natriuretic peptide predicts decreased longer-term physical function after primary coronary artery bypass graft surgery.
abstract: BACKGROUND
  Increased peak postoperative B-type natriuretic peptide (BNP) is associated with increased major adverse cardiovascular events and all-cause mortality after coronary artery bypass graft (CABG) surgery. Whether increased postoperative BNP predicts worse postdischarge physical function (PF) is unknown. We hypothesized that peak postoperative BNP associates with PF assessed up to 2 yr after CABG surgery, even after adjusting for clinical risk factors. including preoperative PF.
  
  
  METHODS
  This two-institution prospective cohort study included patients undergoing primary CABG surgery with cardiopulmonary bypass. Short Form-36 questionnaires were administered to subjects preoperatively and 6 months, 1 yr, and 2 yr postoperatively. Short Form-36 PF domain scores were calculated using the Short Form-36 norm-based scoring algorithm. Plasma BNP concentrations measured preoperatively and on postoperative days 1-5 were log(10) transformed before analysis. To determine whether peak postoperative BNP independently predicts PF scores 6 months through 2 yr after CABG surgery, multivariable longitudinal regression analysis of the postoperative PF scores was performed, adjusting for important clinical risk factors.
  
  
  RESULTS
  A total of 845 subjects (mean ± SD age, 65 ± 10 yr) were analyzed. Peak postoperative BNP was significantly associated with postoperative PF (effect estimate for log(10) peak BNP, -7.66 PF score points [95% CI, -9.68 to -5.64]; P = <0.0001). After multivariable adjustments, peak postoperative BNP remained independently associated with postoperative PF (effect estimate for log(10) peak BNP, -3.06 PF score points [95% CI, -5.15 to -0.97]; P = 0.004).
  
  
  CONCLUSIONS
  Increased peak postoperative BNP independently associates with worse longer-term PF after primary CABG surgery. Future studies are needed to determine whether medical management targeted toward reducing increased postoperative BNP can improve PF after CABG surgery.
authors.affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA. afox@partners.org
authors.forename: Amanda A
authors.initials: AA
authors.lastname: Fox
authors.forename: Edward R
authors.initials: ER
authors.lastname: Marcantonio
authors.forename: Charles D
authors.initials: CD
authors.lastname: Collard
authors.forename: Mathis
authors.initials: M
authors.lastname: Thoma
authors.forename: Tjorvi E
authors.initials: TE
authors.lastname: Perry
authors.forename: Stanton K
authors.initials: SK
authors.lastname: Shernan
authors.forename: Jochen D
authors.initials: JD
authors.lastname: Muehlschlegel
authors.forename: Simon C
authors.initials: SC
authors.lastname: Body
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D011184:Postoperative Period; D011379:Prognosis; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain