title: Preoperative anti-PF4/heparin antibody level predicts adverse outcome after cardiac surgery.
abstract: OBJECTIVE
  Preexisting serum antibodies to heparin/platelet factor 4 complexes may predispose adult cardiac surgical patients to increased perioperative morbidity and mortality. We sought to determine the association between preoperative serum antibodies directed against platelet factor 4/heparin complexes and major complications (in-hospital death or length of stay >10 days) in adult cardiac surgical patients.
  
  
  METHODS
  In a prospective observational study of 466 patients undergoing elective coronary artery bypass grafting, valvular heart surgery, or both, preoperative serum was assayed for anti-platelet factor 4/heparin antibody by using a commercially available enzyme-linked immunosorbent assay (Asserachrom HPIA). Known preoperative risk factors were assessed, and patients were assigned a risk score by using the validated method of Parsonnet and colleagues.
  
  
  RESULTS
  Major complications (death or postoperative hospitalization >10 days) occurred in 108 patients (23%). Overall, 59 (13%) patients had a positive preoperative anti-platelet factor 4/heparin antibody screen (upper limit of normal is 0.5 optical density units). A positive assay result independently predicted an increased risk of major complications (P = .0284; odds ratio, 1.98; 95% confidence interval, 1.06-3.62) over and above the effect of the Parsonnet risk score (P < .001; odds ratio, 1.07; 95% confidence interval, 1.05-1.10). The level of preoperative anti-platelet factor 4/heparin antibody was also significantly associated with major complications (P = .036; odds ratio, 1.31; 95% confidence interval, 1.02-1.68) independently of the Parsonnet risk score. No association (P > .75) existed between the Parsonnet risk score and preoperative anti-platelet factor 4/heparin antibody level.
  
  
  CONCLUSIONS
  Serum antibodies directed against platelet factor 4/heparin complexes are prevalent in the adult patient population undergoing cardiac surgery. The presence of these antibodies before surgery is an independent predictor for death or prolonged hospitalization after adult cardiac surgery.
authors.affiliation: Department of Anesthesiology, Duke University Medical Center, Durham, NC 27710, USA. elliott.bennettguerrero@duke.edu
authors.forename: Elliott
authors.initials: E
authors.lastname: Bennett-Guerrero
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Slaughter
authors.forename: William D
authors.initials: WD
authors.lastname: White
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Welsby
authors.forename: Charles S
authors.initials: CS
authors.lastname: Greenberg
authors.forename: Habib
authors.initials: H
authors.lastname: El-Moalem
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Ortel
mesh_terms: D000368:Aged; D000906:Antibodies / Q000097:blood*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D005260:Female; D006493:Heparin / Q000276:immunology*; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay; D008297:Male; D010978:Platelet Factor 4 / Q000276:immunology*; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011446:Prospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D000906:Antibodies; D010978:Platelet Factor 4; D006493:Heparin