Heparin Induced Thrombocytopenia

HIT or Heparin induced thrombocytopenia is reported in patients who are under the treatment of UFH for 5 or more days. The patients suffering from this complication can develop arterial or venous thrombosis. That is why this subset of symptoms is also known as Heparin Induced Thrombocytopenia and thrombosis syndrome (HITTS). This complication of Heparin is a immune mediated syndrome. Heparin produce specific type of immunoglobulins which bridge the platelets. As a result this mechanism can cause both thrombocytopenia and thrombosis. In some patients the onset of HIT occurs after the discontinuation of the heparin therapy. This condition is known as delayed onset HIT.
Heparin therapy should be immediately stopped on the suspicion of HIT. Laboratory tests are available which can confirm the diagnosis of this complication. As HIT can also cause thrombosis so the patient needs an alternate form of anticoagulant therapy. Some drugs which are used for the therapy of HIT are lepirudin, argatroban and bivalirudin. Argatroban can be given to a patient suffering from HIT and needs PCI for ACS. Argatroban is a direct thrombin inhibitor. Argatroban can be given as a bolus of 240 -mcg/ kg bolus which is followed by 20-mcg/kg infusion per minute. This drug can be given even without GP IIb/IIIa blockade.