title: Effect of anti-platelet factor-4/heparin antibody induction on early saphenous vein graft occlusion after coronary artery bypass surgery.
abstract: BACKGROUND
  Antibodies to complexes of heparin and platelet factor 4 (PF4) are capable of causing heparin-induced thrombocytopenia (HIT). Recent evidence suggests that anti-PF4/heparin antibodies may be prothrombogenic even in the absence of thrombocytopenia and clinically-recognized HIT.
  
  
  OBJECTIVE
  To determine if induction of anti-PF4/heparin antibodies is an independent risk factor for early saphenous vein graft (SVG) occlusion or adverse clinical outcome after coronary artery bypass graft (CABG) surgery.
  
  
  METHODS
  Anti-PF4/heparin antibody titers were measured in 368 patients prior to and then 4 days, 6 weeks and 6 months after CABG surgery. Serotonin release assay (SRA) and antibody isotype analysis were also performed on 6-week samples. SVG patency was determined in 297 patients 6 months after surgery by multidetector computed tomography coronary angiography.
  
  
  RESULTS
  Six weeks after surgery, 52% of patients were anti-PF4/heparin seropositive and 9% were SRA positive. Six months after surgery, neither the percentage of occluded SVG (19% vs. 20%, P = NS), the percentage of patients with an occluded SVG (33% vs. 33%, P = NS) nor the incidence of adverse clinical events (21% vs. 24%, P = NS) differed between seropositive and seronegative groups. Neither IgG isotype nor SRA positivity was additionally predictive of SVG occlusion or adverse clinical outcome.
  
  
  CONCLUSIONS
  Induction of anti-PF4/heparin antibodies, even those capable of heparin-dependent platelet activation, is not independently associated with early SVG occlusion or adverse clinical outcomes after CABG surgery.
authors: Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA.
authors: T J
authors: TJ
authors: Gluckman
authors: J B
authors: JB
authors: Segal
authors: S P
authors: SP
authors: Schulman
authors: E P
authors: EP
authors: Shapiro
authors: T S
authors: TS
authors: Kickler
authors: M M
authors: MM
authors: Prechel
authors: J V
authors: JV
authors: Conte
authors: J M
authors: JM
authors: Walenga
authors: I
authors: I
authors: Shafique
authors: J J
authors: JJ
authors: Rade
mesh_terms: D000328:Adult; D000368:Aged; D001026:Coronary Artery Bypass / Q000379:methods*; D005260:Female; D006083:Graft Occlusion, Vascular / Q000188:drug therapy / Q000601:surgery; D006493:Heparin / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010978:Platelet Factor 4 / Q000737:chemistry / Q000276:immunology*; D011446:Prospective Studies; D012307:Risk Factors; D012501:Saphenous Vein / Q000601:surgery*; D013921:Thrombocytopenia / Q000517:prevention & control; D013927:Thrombosis / Q000628:therapy; D016896:Treatment Outcome
chemical_list: D010978:Platelet Factor 4; D006493:Heparin