Slow It Down: A Case Report Of Microangiopathic Hemolytic Anemia In A Heartmate III Patient

Abstract

<h3>Introduction</h3> Incidence of hemolysis in left ventricular assist devices (LVADs) is reported from 13-18%, but with HeartMate 3 (HM3) LVAD has been decreased to <1%. Typically, hemolysis is associated with LVAD thrombosis with subsequent decreased survival rate at 1 year (38.9% vs. 89.3%). We present a case of microangiopathic hemolytic anemia (MAHA), not related to pump thrombosis in a recent implanted HM3 LVAD patient which resolved by decreasing LVAD speed. <h3>Case Report</h3> A 44 year-old man with status post LVAD HM3 4 months prior complicated with right ventricular (RV) failure, pulmonary hypertension and CKD Stage III was admitted for mixed vasodilatory and cardiogenic shock. Patient required dual inotropes, vasopressors and temporary renal replacement therapy in an effort to stabilize him and continue his evaluation for heart and kidney transplant. Meanwhile, patient developed acute, severe thrombocytopenia (platelet count of 26K) and mild anemia. Disseminated intravascular coagulation was unlikely (normal fibrinogen level). Heparin-induced thrombosis (HIT) antibody testing was non-reactive. No active sepsis. There were no power spikes or suspected LVAD thrombosis (Table 1). Intrinsic bone marrow disease was thought to be unlikely. LDH was elevated and haptoglobin level undetectable (Table 2), blood smear showed schistocytes, raising suspicious for MAHA, therefore LVAD speed was decreased to 5100 RPM to diminish red blood cell (RBC) fragmentation and maintained in systemic unfractionated heparin infusion. This resulted in recovery of platelets and hemolysis parameters (Table 2). Ultimately, patient underwent dual organ transplantation without complications. <h3>Conclusions</h3> Per our knowledge, this is the first case reported of MAHA in a LVAD HM3 patient, not related to pump thrombosis that resolves with decrease in LVAD speed. MAHA is caused by mechanical injury of RBCs. The effective treatment in this scenario was to decrease the speed of the LVAD, hypothetically to decrease excessive shear in circulation. Further research should be done to delineate efficacy of reducing LVAD speed in these patients.