Preoperative heparin therapy causes immune-mediated hypotension upon heparin administration for cardiac surgery.
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.
Casthely
Pierre A
PA
Department of Anesthesia, Division of Cardiac Anesthesia, St Joseph's Regional Medical Center, 703 Main Street,Paterson, NJ 07503, USA. pcasthely@gmail.com
Defilippi
Vincent
V
Cornwell
Lorraine
L
Samuel
Zachary
Z
Yoganathan
Thil
T
Komer
Claudia
C
Cisbarros
Suzanne
S
Acevedo
Alizabeth
A
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
D000906:Antibodies; D000925:Anticoagulants; D006632:Histamine; D006493:Heparin