CARC6: Pharmacologic Optimization Prior to Pump Upgrade: A Novel Algorithm for Treating an Old Problem

Background: Pump thrombosis (PT) remains a known complication of second and some third generation devices, but optimal management of this issue is unclear. We present a case where TEG platelet mapping was successfully used to guide pharmacologic optimization with both intravenous tirofiban and tissue plasminogen activator (tPA), followed by right heart catheterization guided clinical optimization prior to surgical exchange to a more hemocompatible third generation device. Case: A 49-year-old male who had been supported with a HeartWareTM HVADTM for 8 months presented to the hospital with progressive dyspnea and dark urine. After implant he had resumed tobacco use after brief cessation prior to implant; INR was consistently therapeutic, and he was maintained on full dose aspirin per protocol. He presented in decompensated heart failure with an elevated lactate dehydrogenase of 1930IU/L. His LVAD demonstrated a new power increase and a decreased pulse-flow variation. Treatment for pump thrombosis was initiated with a heparin infusion and urine alkalization with sodium bicarbonate. A TEG® platelet mapping™ assay revealed inadequate platelet inhibition. Intravenous glycoprotein IIb/IIa inhibition (GPI) with tirofiban was added to his heparin therapy. Despite over 36 hours of GPI and heparin therapy he had an elevated LDH and abnormal LVAD parameters. The GPI and heparin infusions were discontinued and he was given 35mg of tPA as 5mg bolus followed by 30mg over a 10 hour infusion. Following completion of tPA, his LDH steadily decreased towards normal limits and his LVAD parameters normalized. He then had right heart catheterization performed which revealed elevated biventricular filling pressures and post capillary pulmonary hypertension. He was aggressively diuresed and inotropic support was initiated.. After improvement in his hemodynamics, he underwent successful exchange of his HVAD to a HeartMate 3TM. Discussion: Here we present a case of an LVAD pump thrombosis managed with targeted treatment as guided by TEG® platelet mapping™ and invasive hemodynamics. Society guidelines are broad in their recommendations for anticoagulation and pump exchange. While there are various case reports of acute pump thrombosis treated with either tPA or GPI, there is no consensus guidance for optimal antiplatelet or fibrinolytic therapy. Furthermore, not all published reports on GPI use for pump thrombosis utilize platelet function assays. We propose an algorithm (Fig 1) utilizing TEG® platelet mapping™ to guide targeted antiplatelet or fibrinolytic therapy, followed by right heart catheterization guided optimization to facilitate successful total pump exchange.