Heparin-induced thrombocytopaenia complicating cardiogenic shock requiring durable mechanical circulatory support: a case report

Background: Heparin-induced thrombocytopaenia (HIT) is an immune-mediated reaction to heparin therapy that may lead to life-threatening thrombotic events. This disorder complicates intraoperative heparin use during left ventricular assist device (LVAD) implantation. Case summary: A 52-year-old man presented in acute decompensated heart failure. His admission laboratory studies were consistent with cardiogenic shock with a lactate of 6.1 mmol/L (ref range 0.50-1.99 mmol/L). Echocardiogram and CT scan demonstrated severe biventricular dysfunction and a left ventricular ejection fraction of 10%, as well as left upper lobe segmental pulmonary embolism. He was started on inotropes, diuretics, and a heparin infusion. Following heparin initiation, his platelets had decreased by 63% to a nadir of 39 000/μL (ref range 150 000-450 000/μL) and testing confirmed a diagnosis of HIT. His shock state worsened to INTERMACS 1 necessitating escalation of mechanical support. In preparation for HeartMate 3 LVAD implantation, he received 3 cycles of plasmapheresis with one session of IVIG perioperatively, resulting in a 60% reduction in the titre of heparin-dependent platelet antibodies. He underwent successful LVAD implantation including usage of intraoperative heparin, and was discharged home on post-operative Day 17, where he has remained stable on LVAD support. Discussion: Limited data exist on the perioperative management of patients with HIT undergoing LVAD implantation. Heparin is preferred to other antithrombin agents during surgery due to the availability of an immediate reversal agent. Plasmapheresis with IVIG is a potential management option to decrease heparin-dependent platelet antibodies in patients with HIT to allow for successful LVAD implantation.