Why has the optimal treatment of HIT been difficult to attain?
Optimal treatment of HIT has, until recently, been elusive. The first step of treatment is the elimination of all sources of heparin.[25,30] However, heparin discontinuation itself can be dangerous since the underlying condition, for which heparin was originally instituted, may not yet be resolved.[21] In addition, HIT, a prothrombotic process, requires further anticoagulation with a nonheparin, alternative anticoagulant.[4,25] In HIT, the thrombotic process is amplified by immune complex formation, platelet activation, and thrombin generation even after heparin has been withdrawn.[25] In fact, heparin withdrawal alone results in thrombotic complications in this hypercoagulable state.[25] Many patients, including those without clinical evidence of thrombosis at presentation, go on to develop thrombotic complications even after heparin is discontinued.
