PF4-positive thrombi adhering to the ventricles of Excor-VADs in patients with HIT II

Aims: Thromboembolism is a major complication in patients with ventricular assist devices (VAD). Drug- anticoagulation and the use of biocompatible surfaces such as coating with heparin, aim to reduce thromboembolism in these patients. Administration of heparin can lead to heparin induced thrombocytopenia type II (HIT II) mainly through heparin/platelet factor 4 (HPF4) antibodies. We assessed the presence of PF4-antibodies in VAD-thrombi of patients with heparin-coated VADs and HIT II.