Bilateral lower extremity gangrene requiring amputation associated with heparin-induced thrombocytopenia: a case report.

Heparin is a common cause of thrombocytopenia in hospitalized patients. Between 10% and 15% of patients receiving therapeutic doses of heparin develop thrombocytopenia. Heparin-induced thrombocytopenia (HIT) can cause severe bleeding and thrombosis owing to intravascular platelet aggregation. HIT must be distinguished from other causes of thrombocytopenia. Importantly, heparin use is often associated with an early fall in the platelet count that usually occurs within the first 4 days of initiation and recovers without cessation of heparin treatment. This nonimmune heparin-associated thrombocytopenia has not been found to be associated with thrombosis and does not necessitate discontinuation of heparin. The authors present a case report of a 70-year-old man who received heparin therapy following aortic tissue valve replacement and aortic root repair with graft and developed bilateral lower extremity arterial clots 6 days postoperatively in the setting of positive heparin antibody titers. Ultimately the patient required bilateral above-knee amputations.