Heparin-induced thrombocytopenia: Bovine versus porcine heparin in cardiopulmonary bypass surgery

Background. Studies have demonstrated a high incidence of antibodies to heparin/platelet factor 4 complexes, the antigen in heparin-induced thrombocytopenia, in patients after cardiopulmonary bypass surgery. In many hospitals, beef lung heparin has been used historically for cardiopulmonary bypass, and there has been reluctance to change to porcine heparin despite concerns of an increased incidence of heparin-induced thrombocytopenia in patients receiving bovine heparin. Methods. A prospective randomized trial comparing bovine and porcine heparin in cardiopulmonary bypass surgery was conducted. Presurgery and postsurgery heparin antibody formation was studied using the serotonin release assay and a heparin/platelet factor 4 enzyme-linked immunosorbent assay. Results. Data available on 98 patients, randomized to receive either bovine or porcine heparin, revealed no significant difference in patient positivity by serotonin release assay (12% in both groups) or by the heparin/ platelet factor 4 enzyme-linked immunosorbent assay (29% with porcine and 35% with bovine heparin) postoperatively. There were no significant differences between preoperative and postoperative platelet counts or thromboembolic complications. Conclusions. Our study does not support the belief that bovine heparin is more likely than porcine heparin to induce the development of antibodies to heparin/platelet factor 4.