title: Platelet Counts, Acute Kidney Injury, and Mortality after Coronary Artery Bypass Grafting Surgery.
abstract: BACKGROUND
  Cardiac surgery requiring cardiopulmonary bypass is associated with platelet activation. Because platelets are increasingly recognized as important effectors of ischemia and end-organ inflammatory injury, the authors explored whether postoperative nadir platelet counts are associated with acute kidney injury (AKI) and mortality after coronary artery bypass grafting (CABG) surgery.
  
  
  METHODS
  The authors evaluated 4,217 adult patients who underwent CABG surgery. Postoperative nadir platelet counts were defined as the lowest in-hospital values and were used as a continuous predictor of postoperative AKI and mortality. Nadir values in the lowest 10th percentile were also used as a categorical predictor. Multivariable logistic regression and Cox proportional hazard models examined the association between postoperative platelet counts, postoperative AKI, and mortality.
  
  
  RESULTS
  The median postoperative nadir platelet count was 121 × 10/l. The incidence of postoperative AKI was 54%, including 9.5% (215 patients) and 3.4% (76 patients) who experienced stages II and III AKI, respectively. For every 30 × 10/l decrease in platelet counts, the risk for postoperative AKI increased by 14% (adjusted odds ratio, 1.14; 95% CI, 1.09 to 1.20; P < 0.0001). Patients with platelet counts in the lowest 10th percentile were three times more likely to progress to a higher severity of postoperative AKI (adjusted proportional odds ratio, 3.04; 95% CI, 2.26 to 4.07; P < 0.0001) and had associated increased risk for mortality immediately after surgery (adjusted hazard ratio, 5.46; 95% CI, 3.79 to 7.89; P < 0.0001).
  
  
  CONCLUSIONS
  The authors found a significant association between postoperative nadir platelet counts and AKI and short-term mortality after CABG surgery.
authors.affiliation: From the Division of Cardiothoracic Anesthesiology and Critical Care Medicine, Department of Anesthesiology (M.D.K., S.Z., J.A.K., M.C., E.J., W.D.W., S.A., M.V.P., I.J.W., J.H.L., M.S.-S., J.P.M.), Department of Biostatistics and Bioinformatics and Molecular Physiology Institute (Y.-J.L.), Division of Cardiovascular and Thoracic Surgery, Department of Surgery (J.G.), Duke University Medical Center, Durham, North Carolina; and Division of Cardiac Anesthesiology and Critical Care Medicine, Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut (M.L.F.).
authors.forename: Miklos D
authors.initials: MD
authors.lastname: Kertai
authors.forename: Shan
authors.initials: S
authors.lastname: Zhou
authors.forename: Jörn A
authors.initials: JA
authors.lastname: Karhausen
authors.forename: Mary
authors.initials: M
authors.lastname: Cooter
authors.forename: Edmund
authors.initials: E
authors.lastname: Jooste
authors.forename: Yi-Ju
authors.initials: YJ
authors.lastname: Li
authors.forename: William D
authors.initials: WD
authors.lastname: White
authors.forename: Solomon
authors.initials: S
authors.lastname: Aronson
authors.forename: Mihai V
authors.initials: MV
authors.lastname: Podgoreanu
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Gaca
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Welsby
authors.forename: Jerrold H
authors.initials: JH
authors.lastname: Levy
authors.forename: Mark
authors.initials: M
authors.lastname: Stafford-Smith
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Mathew
authors.forename: Manuel L
authors.initials: ML
authors.lastname: Fontes
mesh_terms: D058186:Acute Kidney Injury / Q000453:epidemiology*; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D009657:North Carolina / Q000453:epidemiology; D010976:Platelet Count / Q000706:statistics & numerical data*; D011183:Postoperative Complications / Q000453:epidemiology*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome