Abstract
Background. Heparin induced thrombocytopenia (HIT) is a relatively rare condition burdened by a high rate of complications and mortality. It is always crucial to keep HIT in mind in thrombocytopenic patients, even when other causes are highly suspected or documented. Alternative anticoagulants to heparin are required to avoid life-threatening complications. Warfarin is also contraindicated in acute HIT. Danaparoid, is the only anticoagulant whose mechanism of action thoroughly counteract the pathogenesis of HIT. However, it can hardly be applied to major surgery due to its 24-hour half-life.
Case Presentation. Here we present a case of HIT occurred after cardiac surgery, from which multiple suggestions could be derived on the real-word management of this challenging condition. Warfarin was initiated soon after valve surgery, according to our institutional protocol. Unfortunately, HIT was initially underestimated because an infectious hypothesis appeared much more plausible and strongly supported by echocardiography. Unexpectedly, a life-threatening left atrium thrombosis appeared at a second surgery that had been indicated because of endocarditis. Thus, we realized that thrombosis occurred soon after discontinuation and reversal of warfarin, which was decided because of the high risk of bleeding due to both severe thrombocytopenia and vitamin K antagonism.
Conclusions. Warfarin discontinuation could lead to catastrophic consequences if an unrecognized HIT is ongoing, and an alternative anticoagulant is not initiated. Danaparoid was used to treat HIT after the diagnosis was made. Monitoring its anti-Xa activity allowed anticoagulation to be adapted both when invasive procedure was needed and when the decision to switch to warfarin was made, thus balancing the risk of both bleeding and thrombosis in a patient with HIT who had recently undergone heart surgery.