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

Background. Studies have demonstrated a high incidence of antibodies to hep arin/platelet factor 4 complexes, the antigen in heparin-induced thrombocyt openia, 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 hepari n in cardiopulmonary bypass surgery was conducted. Presurgery and postsurge ry 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 positivi ty by serotonin release assay (12% in both groups) or by the heparin/ plate let factor 4 enzyme-linked immunosorbent assay (29% with porcine and 35% wi th bovine heparin) postoperatively. There were no significant differences b etween preoperative and postoperative platelet counts or thromboembolic com plications. Conclusions. Our study does not support the belief that bovine heparin is m ore likely than porcine heparin to induce the development of antibodies to heparin/platelet factor 4.