Heparin induced thrombocytopenia: diagnosis and treatment

Abstract

Heparin is the most common anticoagulant drug used in the clinical practice. Heparin-induced thrombocytopenia (HIT) is an immuno-hematologic syndrome that results from platelets activation in patients under heparin therapy. The incidence of HIT is about 1 to 6%. It might be classified in type I and II, this last is potentially lethal. Clinical and laboratorial findings are both mandatory to diagnostic confirmation, as well as positivity for HIT antibody. The Warkentin probability scale helps on HIT diagnosis and has a high negative predictive value. A clinical approach that includes heparin discontinuation is mandatory. An alternative anticoagulation therapy must be initiated and the direct inhibitors of thrombin are the preferred drugs. Foundaparinux has showed benefits in this context, although randomized clinical trials are needed for better evidence.