HEPARIN-ASSOCIATED ANTIBODIES AND ADVERSE OUTCOMES FOLLOWING CARDIAC SURGERY

Abstract

Introduction: Heparin-associated thrombocytopenia and thrombosis has long been recognized as a potential complication of heparin administration. Recently, antibodies to the heparin/PF4 complex have been identified as the molecular mediator of thrombocytopenia and thrombosis associated with heparin therapy. Retrospective studies suggest that the preoperative presence of heparin-associated antibodies is associated with adverse outcomes following cardiac surgery. [1] We sought to define the prevalence of the heparin-PF4 antibody in our population and to prospectively examine the association between heparin-associated antibodies and adverse outcomes following cardiac surgery. Methods: Preoperative blood samples were obtained from 85 patients scheduled to undergo cardiac surgery. Heparin-associated antibodies were measured using an ELISA for antibodies to heparin/PF4 complexes. Adverse outcome was defined as either in-hospital death or postoperative length of stay greater than 10 days. Differences in patient comorbidities and expected surgical risk were controlled for using the validated Parsonnet scoring system. [2] Results: Heparin-associated antibodies were detected in 8 of 85 patients (9.4%). Adverse outcomes, as previously defined, occurred in 10 of 85 patients (11.8%). After adjusting for comorbidities, no correlation was observed between the preoperative presence of heparin-associated antibodies and adverse outcome. There were no statistically significant differences in patient demographics, CPB time, cross-clamp time, inotrope use, or blood products transfused. Discussion: The prevalence of heparin-associated antibodies in preoperative cardiac surgical patients is greater than previously recognized. [1] Although we observed no association between heparin/PF4 antibodies and adverse outcome following cardiac surgery, a larger sample size will be required to definitively verify this conclusion.