Two Cases of Valvular Thrombosis Secondary to Heparin-Induced Thrombocytopenia Managed Without Surgery

A 83-year-old woman underwent aortic valvular replacement with a bioprosthesis for symptomatic aortic stenosis. Anesthesia and surgery were uneventful. Unfractionated heparin (UFH) had been administered for cardiopulmonary bypass followed by anticoagulation on day 0 (surgery), and had been continued thereafter. Routine postoperative blood count showed an increase in platelet counts to >200 g/L on day 6. On the ninth day, the patient complained of paresthesia of the left foot. A computed tomography scan with intravenous radiocontrast material was performed. Thrombosis of both iliofemoral axes and a thrombus on the ascending aorta were found (Figure 1 and Figure 2). A blood count on day 9 revealed thrombopenia at 44 G/L; antiPF4 antibodies (Enzyme-Linked ImmunoSorbent Assay HPIA is Heparin Platelet Factor 4 Induced Antibodies [ELISA] Asserachrom HPIA Stago, Asnieres France) were positive (optical density >2), and the platelet aggregation test confirmed the diagnosis of heparin-induced thrombocytopenia. Anticoagulation with UFH was stopped and replaced with intravenous sodium danaparoid targeted to anti-Xa concentration of 0.5 to 0.8 IU/mL. The patient underwent surgical iliofemoral thrombectomy that was uneventful.Figure 1. Computed tomography …