What is the recommended management step when HIT is suspected?

• A. Stop heparin and start a non-heparin anticoagulant
• B. Continue heparin and monitor
• C. Platelet transfusion only
• D. Start warfarin immediately with heparin

Answer: (A)

When HIT is suspected, the priority is to stop all heparin exposure and initiate an alternative anticoagulant that does not cross-react with HIT antibodies (for example, argatroban, bivalirudin, or fondaparinux). This immune-mediated reaction forms antibodies against the heparin–PF4 complex, which activates platelets and drives a dangerous prothrombotic state even as the platelet count falls. Keeping heparin on board would continue to fuel clot formation, so stopping it is essential.

Platelet transfusion is not routinely used in HIT because adding platelets can provide more material for the immune system to activate and may worsen thrombosis, unless there is life-threatening bleeding.

Starting warfarin right away is avoided in the acute phase of HIT. Warfarin can precipitate or worsen thrombosis by lowering protein C early in treatment, potentially leading to skin necrosis or limb gangrene. After a non-heparin anticoagulant is in place and platelets have recovered, patients may be transitioned to an oral anticoagulant with careful monitoring, often with a bridging strategy as needed.