Incidence of heparin-induced thrombocytopenia and therapeutic strategies in pediatric cardiac surgery

Abstract

Background: We identified the incidence of heparin-induced thrombocytopenia and the antiheparin-platelet factor 4 (PF4) antibody in pediatric patients undergoing cardiac surgery and documented the differences in the anticoagulation management for the extracorporeal circulation.

Methods: Between January 2001 and September 2003, 559 cardiac procedures with extracorporeal circulation in 415 patients with congenital heart defects were performed in our institution. Because the development of heparin-induced thrombocytopenia requires previous exposition to heparin, only the 144 patients undergoing a scheduled second procedure on extracorporeal circulation were screened preoperatively. Of these 144 patients, 41 underwent also a third procedure and were screened before each procedure for presence of antiheparin-PF4 antibodies and for clinical signs of heparin-induced thrombocytopenia.

Results: The incidence of antiheparin-PF4 antibodies during the study period was 1.4% (2 of 144 patients). Patients with clinically significant heparin-induced thrombocytopenia could not be identified. Outside the study protocol, 2 more patients with antiheparin-PF4 antibodies were found. In these 4 patients, surgery was performed using lepirudin (Schering, Berlin, Germany) instead of the usual heparin management for extracorporeal circulation. Three of these 4 patients had an uneventful procedure and postoperative course. In 1 patient after total cavopulmonary connection, a reoperation was necessary on the seventh postoperative day owing to partial thrombosis of the lateral tunnel.

Conclusions: The incidence of heparin-induced thrombocytopenia and of antiheparin-PF4 antibodies in patients undergoing repeated cardiac surgery is low. In antiheparin-PF4 antibody positive patients, the complete avoidance of heparin can be achieved and may account for an uneventful perioperative course.