Heparin-induced thrombocytopenia post-cardiovascular interventional therapy: a case report

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is an antibody-mediated adverse drug reaction characterized by thrombocytopenia and thromboembolism. Herein, we present a case of HIT with subcutaneous hemorrhage after cardiovascular interventional therapy. CASE PRESENTATION: A 74-year-old man was admitted to the hospital for elective atrial fibrillation (AF) catheter ablation and left atrial appendage closure because of intermittent dizziness and palpitations. At presentation, the routine laboratory test results showed no abnormalities. He received subcutaneous enoxaparin for stroke prevention and unfractionated heparin for intraprocedural anticoagulation during coronary angiography and the AF procedure. On the second day after the AF procedure, the patient developed profound thrombocytopenia, moderate anemia, and mild subcutaneous hematoma. Blood tests and imaging examinations excluded acute hemolysis and other active bleeding. A 4Ts score of 5 and markedly positive platelet factor 4 IgG antibody established the diagnosis of HIT. Due to progressive subcutaneous hemorrhage in the thighs that could not be suppressed by pressure dressing, the patient received platelet transfusion and rivaroxaban for anticoagulation. The following days, the patient remained clinically stable from the hemorrhage, and his platelet count recovered. No thrombotic events occurred during hospitalization or follow-up. CONCLUSION: This case emphasizes the significance of suspecting HIT in patients with unexplained rapid thrombocytopenia after frequent heparin exposure. Decision-making regarding alternative anticoagulation and platelet transfusion in HIT with hemorrhage must be based on unique patient characteristics.