title: Positive heparin-platelet factor 4 antibody complex and cardiac surgical outcomes.
abstract: BACKGROUND
  Given the large number of patients undergoing cardiac operations annually, it is important to identify populations at high risk for adverse outcomes. This observational study was conducted to determine the incidence of preoperative heparin-platelet factor 4 (HPF4) antibodies and to assess the associated risk of postoperative adverse outcomes in a nonselected cardiac surgery patient population.
  
  
  METHODS
  Between March 2002 and December 2004, 1114 (92%) of 1209 patients undergoing cardiac surgery with heparin were tested in an unselected manner for HPF4 antibodies. Main outcome measures were HPF4 antibody seropositivity and fatal and nonfatal adverse clinical outcomes after cardiac surgery.
  
  
  RESULTS
  Of those screened, 60 (5.4%) of 1114 had positive HPF4 antibodies preoperatively. These patients had longer mean postoperative length of stay (14.0 days versus 9.8 days, p = 0.05), a higher incidence of prolonged (> or = 96 hours) mechanical ventilation (20.3% versus 9.2%, p = 0.02), acute limb ischemia (5.1% versus 0.9%, p = 0.03), renal complications including dialysis (20.3% versus 10.5%, p = 0.03), and gastrointestinal complications (15.3% versus 5.9%, p = 0.01). Stepwise logistic regression analysis showed positive HPF4 antibody status to be an independent predictor for adverse outcome and was associated with a higher risk for renal complications, including dialysis (adjusted odds ratio 2.2; 95% confidence interval, 1.1 to 4.3), than was diabetes.
  
  
  CONCLUSIONS
  In this large patient series, the presence of HPF4 antibodies before surgical heparin administration was an independent and clinically significant risk factor for postoperative adverse events after cardiac surgery. An optimal preoperative cardiac surgery risk profile should include HPF4 antibody status.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, St. Luke's Medical Center, Milwaukee, Wisconsin, USA. dkress2003@msn.com
authors.forename: David C
authors.initials: DC
authors.lastname: Kress
authors.forename: Solomon
authors.initials: S
authors.lastname: Aronson
authors.forename: Monica L
authors.initials: ML
authors.lastname: McDonald
authors.forename: Mohammad I
authors.initials: MI
authors.lastname: Malik
authors.forename: Ajit B
authors.initials: AB
authors.lastname: Divgi
authors.forename: Alfred J
authors.initials: AJ
authors.lastname: Tector
authors.forename: Francis X
authors.initials: FX
authors.lastname: Downey
authors.forename: Alfred J
authors.initials: AJ
authors.lastname: Anderson
authors.forename: Mia
authors.initials: M
authors.lastname: Stone
authors.forename: Cassandra
authors.initials: C
authors.lastname: Clancy
mesh_terms: D000368:Aged; D000906:Antibodies; D000925:Anticoagulants / Q000009:adverse effects / Q000276:immunology*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D005260:Female; D006493:Heparin / Q000009:adverse effects / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010978:Platelet Factor 4 / Q000276:immunology*; D012189:Retrospective Studies; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000276:immunology; D016896:Treatment Outcome
chemical_list: D000906:Antibodies; D000925:Anticoagulants; D010978:Platelet Factor 4; D006493:Heparin