Heparin-induced thrombocytopenia during anticoagulation therapy for COVID-19-related pulmonary embolism: A case report

Rationale:One of the main characteristics of COVID-19 is the high incidence of venous thromboembolism, particularly pulmonary embolism. Anticoagulation therapy is the primary treatment for pulmonary embolism. Heparin-induced thrombocytopenia (HIT) is an antibody-mediated adverse reaction to heparin that occurs during its use of heparin drugs. The main clinical manifestation is a decrease in platelet count, which can lead to the formation of arterial and venous thrombosis and, in severe cases, even death. Herein, we present a case of HIT that occurred during anticoagulation therapy for COVID-19, complicated by pulmonary embolism.Patient concerns:An 86-year-old man with COVID-19 experienced a significant decrease in platelet count and progression of venous thrombosis in the lower extremities during anticoagulation therapy with nadroparin.Diagnoses:The 4T score was 6; therefore, HIT was considered.Interventions and outcomes:All heparin-based drugs were discontinued, and argatroban was administered as anticoagulation therapy. The patient's platelet count was monitored, and it gradually returned to normal.Lessons:Clinicians should remain vigilant to venous thromboembolism for COVID-19 patients even after recovery. During anticoagulant therapy, if thrombocytopenia occurs, HIT should be considered due to its high mortality rate. The 4T scoring system was used for the initial assessment. HIT antibodies can be detected, if necessary, to assist in diagnosis and reduce the occurrence of severe HIT. In the future, by detecting certain biomarkers, we can screen out patients with HIT who are more prone to thrombotic events, thereby minimizing the risk of bleeding caused by anticoagulation.