HEPARIN-INDUCED THROMBOCYTOPENIA

Heparin-induced thrombocytopenia (HIT) is a rare complication of hepar in with significant morbidity and mortality. In this study, a retrospe ctive review of all patients referred to the platelet study lab at Eas t Carolina University who tested positive for heparin-induced platelet aggregation was performed. From May 1988 through March 1991, 40 patie nts with clinically suspected HIT were referred for platelet aggregati on studies. Ten patients tested positive for in-vitro platelet aggrega tion in the presence of heparin. The clinical characteristics of these patients are reviewed. Results show a preponderance of surgical patie nts with 8/10 patients having undergone a primary major surgical proce dure. Six of the eight surgical patients underwent a major vascular or cardiac procedure. The mortality rate for patients with heparin-induc ed in-vitro platelet aggregation was 30 per cent. Major thromboembolic morbidity was substantial (80%) with 5/10 patients requiring an extre mity amputation. The estimated incidence of HIT in surgical patients i n this series was 0.3 per cent. HIT is an unusual complication of hepa rin therapy with devastating morbidity and mortality. Patients undergo ing a major vascular or cardiac procedure appear to be at increased ri sk. Increased awareness of the syndrome and careful monitoring of plat elet counts in patients at high risk may reduce the morbidity and mort ality