title: Preoperative heparin therapy causes immune-mediated hypotension upon heparin administration for cardiac surgery.
abstract: OBJECTIVE
  To evaluate whether patients with positive or negative heparin antibodies who received heparin preoperatively by continuous infusion developed cardiovascular changes upon heparin administration prior to cardiopulmonary bypass.
  
  
  METHODS
  Clinical trial.
  
  
  METHODS
  Single institution, academic hospital.
  
  
  METHODS
  Eighty (80) patients with good ventricular function on low-dose heparin infusion prior to surgery.
  
  
  METHODS
  Patients were divided into 2 equal groups: group A had negative heparin antibodies (% ratio < 0.26), group B had positive heparin antibodies (% ratio > 1.2). All patients received heparin, 400 units/kg, prior to institution of cardiopulmonary bypass. Cardiovascular changes, activated coagulation time (ACT), and histamine levels were measured before and 5 minutes after administration of heparin. Platelets also were counted before and 6 hours after surgery.
  
  
  RESULTS
  Significant hypotension and decreased cardiac index occurred in patients with positive heparin antibodies who received heparin prior to cardiac surgery. Histamine levels increased significantly 5 minutes after heparin administration. Significant thrombocytopenia occurred 6 hours after surgery in group B patients. There was a good correlation between heparin antibodies, histamine levels, thrombocytopenia and cardiovascular changes. Group B patients also had heparin resistance as manifested by a lower ACT after the loading doses of heparin.
  
  
  CONCLUSIONS
  Patients with positive heparin antibodies pretreated with heparin prior to surgery developed a type of immune-mediated cardiovascular changes and postoperative thrombocytopenia.
authors.affiliation: Department of Anesthesia, Division of Cardiac Anesthesia, St Joseph's Regional Medical Center, 703 Main Street,Paterson, NJ 07503, USA. pcasthely@gmail.com
authors.forename: Pierre A
authors.initials: PA
authors.lastname: Casthely
authors.forename: Vincent
authors.initials: V
authors.lastname: Defilippi
authors.forename: Lorraine
authors.initials: L
authors.lastname: Cornwell
authors.forename: Zachary
authors.initials: Z
authors.lastname: Samuel
authors.forename: Thil
authors.initials: T
authors.lastname: Yoganathan
authors.forename: Claudia
authors.initials: C
authors.lastname: Komer
authors.forename: Suzanne
authors.initials: S
authors.lastname: Cisbarros
authors.forename: Alizabeth
authors.initials: A
authors.lastname: Acevedo
mesh_terms: D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood*; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology; D001026:Coronary Artery Bypass / Q000379:methods*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology; D006632:Histamine / Q000097:blood; D006801:Humans; D007022:Hypotension / Q000139:chemically induced / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011300:Preoperative Care; D011446:Prospective Studies; D013921:Thrombocytopenia / Q000139:chemically induced / Q000276:immunology; D014914:Whole Blood Coagulation Time
chemical_list: D000906:Antibodies; D000925:Anticoagulants; D006632:Histamine; D006493:Heparin