A Hemolytic Event in a Heartmate 3 Patient in the Setting of Polycythemia

Introduction The Heartmate 3 (HM3) LVAD has significantly reduced hemocompatibility events. We present a case of a hemolytic event in a HM3 patient likely related to underling polycythemia. Case Report A 49-year-old man with multisystem sarcoidosis (pulmonary and cardiac) complicated by stage D systolic heart failure status post HeartMate 3 left ventricular assist device (LVAD) implantation and secondary polycythemia attributed to chronic hypoxic respiratory disease and pulmonary hypertension presented with symptoms of left arm numbness and tingling followed by severe substernal chest pain. Initial examination was unremarkable. EKG revealed nonspecific intraventricular conduction delay. Troponin I was elevated at 6.1. Hemoglobin was elevated to 19. LDH was elevated to LDH 568 from baseline of 300s. INR was 1.6 upon arrival. LVAD interrogation revealed speed 5600 rpm, flow 4.5 L/min, power 4.4 Watts and pulsatility index of 4.8. Heparin drip, aspirin and statin were initiated for presumed NSTEMI. LDH remained elevated to 600s. Left heart catherization revealed an acute clot in mid-circumflex associated with 50% stenosis consistent with partial resolution of thrombosis. Further workup revealed normal haptoglobin, erythropoietin and total bilirubin levels however plasma free hemoglobin was elevated to 63.1. Urine hemoglobin was not detected. A JAK2 mutation was excluded. Slow therapeutic phlebotomies with replacement of 125cc of blood with equivalent normal saline were initiated given concern for hemolytic event in the setting of worsening polycythemia. Renal imaging was negative and pretest probability for hematologic malignancies remained low. Of note, the patient reported non-compliance with home oxygen therapy used only at the time of exertion. Compliance was reinforced. Subsequently, LDH trended down to baseline following successful heparin bridge to therapeutic warfarin level. The patient was discharged in stable condition. Summary An acute hemolytic event (and possible cardioembolic NSTEMI) was seen in our patient evidenced by an elevation of LDH, plasma hemoglobin and new coronary thrombus in the setting of worsening polycythemia. Despite a remarkable low rate of pump thrombosis, HM3 recipients with acquired pro-thrombotic states such as polycythemia maybe at risk for adverse hemocompatibility events. Close surveillance is warranted for these special populations.