Successful Heartmate 3 LVAD Implantation in a Patient with Heparin Induced Thrombocytopenia Using Pre-Implantation Plasmapheresis and Intraoperative Continuous Prostacyclin

Abstract

Introduction Heparin Induced Thrombocytopenia (HIT) describes a prothrombotic state with significant rates of thrombus formation. We present a rare case of successful implantation of a HeartMate 3 left ventricular assist device (LVAD) in a patient with HIT using pre-transplant plasmapheresis followed by intraoperative prostacyclin administration. Case presentation A 48-year-old male with history of three vessel CAD and ischemic cardiomyopathy presented with symptoms of shortness of breath. Initial plans for CABG were cancelled given critically low ejection fraction of 15%, lack of myocardial viability and moderate to severe mitral regurgitation. He was subsequently evaluated for surgical AHF therapies. In pre-transplant testing, platelets were 296. An intra-aortic balloon pump was placed for hemodynamic optimization with peri-procedural heparin utilization. Shortly thereafter, his platelets fell to 136. HIT was suspected by ELISA testing with initial optical density (OD) of anti- platelet factor 4 (PF4) of 1.255, confirmatory testing with serotonin release assay was positive at 87%. Anticoagulation was switched to argatroban. Due to clinical deterioration, urgent LVAD implantation was planned. He underwent five sessions of plasmapheresis (PP) every other day to reduce circulating PF4 antibodies prior to implantation (Figure). PP sessions included replacement of total plasma volume with 5% albumin followed by saline over two hours. Anti-PF4 OD levels decreased to 0.987 following first session. Subsequent levels fell to 0.570, 0.348 and 0.153 following the second, third and fourth sessions. He underwent his fifth session of plasmapheresis during Heartmate 3 LVAD implantation. A continuous infusion of epoprostenol starting at an infusion of 15 ng/kg/min was initiated 30 minutes before intra-operative heparin administration and titrated to a dose of 30 ng/kg/min. Epoprostenol was discontinued 15 minutes after protamine reversal at the conclusion of the case. Post-operative Anti-PF4 levels were 0.114. He developed DIC with INR 4.1, PT 39.7, PTT 107.4 and Fibrinogen 70 following implantation requiring Factor 7 administration. The patient is doing well 3 months post-LVAD implantation and is being considered for heart transplantation. Discussion HIT can be a barrier to advanced surgical AHF therapies. Pre-implantation plasmapheresis followed by intraoperative continuous prostacyclin administration is an effective and safe method to reduce anti-PF4 levels and platelet activation and thus the risk of thrombosis.