Evaluation of the use of direct oral anticoagulants for the management of heparin-induced thrombocytopenia

Management of Heparin-Induced Thrombocytopenia: A Contemporary Review

Heparin-induced thrombocytopenia (HIT) is a life- and limb-threatening immune-mediated emergency classically associated with heparin therapy. This review focuses on type II HIT, characterized by the development of antibodies against platelet-factor 4 (PF4) bound to heparin after exposure, causing life-threatening thrombocytopenia, arterial thrombosis, and/or venous thrombosis. The high morbidity and mortality rates emphasize the need for early recognition and urgent intervention with discontinuation of heparin and initiation of non-heparin anticoagulation. We discuss the management of HIT with an emphasis on recent developments: (i) incorporating the phases of HIT (i.e., suspected, acute, subacute A and B, and remote) into its management, categorized according to platelet count, immunoassay, and functional assay results and (ii) direct-acting oral anticoagulants (DOACs), which are increasingly used in appropriate cases of acute HIT (off-label). In comparison to parenteral options (e.g., bivalirudin and danaparoid), they are easier to administer, are more cost-effective, and obviate the need for transition to an oral anticoagulant after platelet recovery. We also identify the knowledge gaps and suggest areas for future research.

Successful Treatment With the Oral Factor Xa Inhibitor Edoxaban in Heparin-Induced Thrombocytopenia With Thrombosis

Heparin-induced thrombocytopenia with thrombosis (HITT) is a rare immune reaction to the drug heparin that causes increased blood clotting, putting patients at risk for arterial and venous thromboembolism which can have severe consequences. We present a case of HITT successfully treated with the direct oral anticoagulant (DOAC), edoxaban. A 56-year-old man had surgery to remove a colorectal mass. After discharge, he developed chest discomfort, shortness of breath, and low oxygen levels and was diagnosed with a right-sided lobar pulmonary embolism. His platelet count dropped, his tests confirmed a diagnosis of HITT, and he was initially treated with fondaparinux. After showing clinical and laboratory improvement, he was switched to edoxaban. Despite being diagnosed with colonic adenocarcinoma during follow-up, the patient's platelet count returned to normal, and he did not experience any more blood clots or serious bleeding events. The use of DOACs like edoxaban as potential therapies for HITT is promising; further research is being conducted to evaluate their effectiveness, safety, and potential benefits for treating this acquired high-risk thrombophilia.