Therapeutic Plasma Exchange for Treatment of Heparin Induced Thrombocytopenia in a Patient Undergoing Left Ventricular Assist Device Implantation

Abstract

Introduction Heparin-induced thrombocytopenia (HIT) is an autoimmune reaction to heparin exposure that is associated with a high morbidity and mortality. HIT occurs when platelet factor 4 (PF4) antibodies are released and bind to exogenous heparin. This creates complexes that may induce a life-threatening systemic coagulopathy. Standard treatment for HIT includes discontinuation of heparin and administration an alternative thrombin inhibitor. We report a case of a man who developed HIT prior to left ventricular assist device (LVAD) implantation, a procedure which requires a large dose of intraoperative heparin. The patient was treated with therapeutic plasma exchange (TPE) and was able to safely undergo LVAD implantation. Case Report A 52-year-old Caucasian man was initially admitted for a delayed presentation ST elevation myocardial infarction. He underwent left anterior descending coronary artery (LAD) stent placement and was discharged home on appropriate medical therapy but with significant residual left ventricular dysfunction. The patient returned three weeks later in cardiogenic shock requiring emergent extracorporeal membrane oxygenation (ECMO) placement with a heparin drip per protocol. He was weaned off ECMO and transitioned to Impella support. Labs for thrombocytopenia revealed HIT which was confirmed with a positive serotonin release assay (SRA). For refractory shock and an echocardiogram which showed an ejection fraction of 10-15%, the patient was approved for durable LVAD implantation. TPE was initiated to remove the PF4 antibodies. Using optical density as a guide, the patient underwent five rounds of TPE until he was SRA negative. He then uneventfully received heparin during LVAD implantation. Post procedure, the patient was started on argatroban with warfarin until his INR was therapeutic. The patient was discharged one-month post procedure. He has completed a course of rehab and is now functionally class I with plans for a transplant evaluation. Summary To our knowledge this is the first case report of the use of optical density guided TPE for HIT in a patient undergoing LVAD implantation. The treatment required a multidisciplinary approach and led to an excellent outcome in a critically ill patient.