Ischemic Stroke and Bilateral Pulmonary Embolism in COVID-19: COVID-Associated Coagulopathy or Heparin-Induced Thrombocytopenia

A main feature of coronavirus disease 2019 (COVID-19) pathogenesis is the high frequency of thrombosis, predominantly pulmonary embolism (PE). Anticoagulation therapy is a crucial part of the management. Heparin use for anticoagulation could increase the risk of heparin-induced thrombocytopenia (HIT), a potentially fatal complication that presents with thrombocytopenia with or without thrombosis. We present a 69-year-old unvaccinated female patient with severe COVID-19 pneumonia. Initial laboratory investigation was significant for thrombocytopenia and low D-dimer levels. She was initially started on enoxaparin followed by unfractionated heparin. On hospital day 8, she developed left facial droop and dysarthria and was found to have non-occlusive thrombus in proximal middle cerebral artery as well as bilateral pulmonary emboli. She received intravenous thrombolysis followed by heparin infusion. On day 13 of hospitalization, platelet count dropped from 120,000/mm3 to 43,000/mm3, raising suspicion of HIT. Heparin was stopped and fondaparinux was started. After 3 days, HIT antibody testing returned positive, then a positive serotonin release assay confirmed the diagnosis. On discharge, she was transitioned to apixaban to complete 3 months of anticoagulation for provoked PE. This case represents the diagnostic challenge of HIT in COVID-19 patients. Thrombocytopenia after heparin infusion should raise clinical suspicion of HIT, which allows appropriate discontinuation of heparin products and initiation of alternative anticoagulants to limit devastating complications. To our knowledge, this is the first case report of a COVID-19 patient presenting with venous thrombosis as well as arterial thrombotic event in the context of underlying HIT.