Recurrent Pump Thromboses in an LVAD Patient with Chronic Lymphocytic Leukemia

Abstract

<h3>Introduction</h3> There is limited literature regarding the management of LVAD patients with concomitant hematologic malignancies. This case report describes a patient with chronic lymphocytic leukemia (CLL) who developed recurrent pump thromboses after LVAD implantation. <h3>Case Report</h3> A 66-year-old man with a past medical history of ischemic cardiomyopathy requiring HeartWare implant, CLL, and secondary polycythemia presents with recurrent pump thromboses. After an uneventful 17 months, the patient presented with gross hematuria, elevated LDH, and high pump parameters. Chronic antithrombotic therapy (AT) was per center protocol with warfarin (goal INR 2-3, time in therapeutic range [TTR] 65%) and aspirin. Hgb levels were elevated with an average of 14.0g/dL over the prior 3 months. Upon admission, he was treated with heparin without improvement in LDH or symptoms. Therapy was then escalated to alteplase (two bolus regimen of 10mg push over 1 minute and a 1mg/min push over 20 minutes followed by an extended infusion dosed at 1mg/hr for 45 hours), with improvement in LDH, pump parameters, and no adverse events. AT was intensified at discharge (INR goal 2.5-3.0, ticagrelor added) and oncology was consulted to manage Hgb levels outpatient with therapeutic phlebotomy for a goal of <12g/dL. Patient had 2 more events of pump thromboses, 2.5 and 15 months after the first and second events, respectively - both of which responded to alteplase. Hgb was at goal after the first event but was temporarily elevated 8 months prior to third event following a course of IV iron. After the second event, AT was altered to enoxaparin 1mg/kg q12hr and aspirin, given warfarin failure (two thrombotic events with above average TTR); ticagrelor was discontinued in the event an urgent pump exchange was needed. After the third event, AT was intensified again by resuming ticagrelor. Pump exchange was deferred given improvements in LDH and resolution of symptoms. In an LVAD patient with CLL, escalating AT was insufficient. Targeting a lower Hgb level, to reduce the resistance within the pump, may be beneficial. <h3>Summary</h3> Hematologic malignancies can pose an increased risk of thrombosis despite appropriate anticoagulation, and management can be challenging in LVAD patients. More aggressive control of hemoglobin in addition to adequate anticoagulation is critical in managing these patients.