Outcomes With Impella 5.0 And 5.5 In Cardiogenic Shock

Abstract

<h3>Background</h3> : Cardiogenic shock is associated with a mortality rate between 40-60%, and as high as 70% in the setting of ST-elevation myocardial infarction.^1-5 In patients with cardiogenic shock, mechanical support is often needed for temporary support as a bridge to decision. The Impella 5.0 and 5.5 (Abiomed, Danvers, Massachusetts) micro-axial pumps are left ventricular assist devices (LVAD) that pull blood from the left ventricle into the ascending aorta.⁶ We sought to describe outcomes and potential complications associated with extended Impella 5.5 and 5.0 in cardiogenic shock. <h3>Methods</h3> We retrospectively evaluated patients who underwent implantation of Impella 5.0 and 5.5 in the operating room due to cardiogenic shock between August 1^st, 2018 and December 31^st, 2020 at our institution. Hemolysis was defined as plasma free hemoglobin level above 50 mg/dL, a lactate dehydrogenase (LDH) level above 500 units/L, and bilirubin increase above 1 mg/dL. <h3>Results</h3> 19 patients underwent insertion of Impella 5.0 or 5.5 in the operating room with 14 patients receiving Impella 5.5 and 5 receiving Impella 5.0. Devices were placed in the axillary artery (14), ascending aorta (3), and carotid artery (2). Mean age was 52.6 ± 13.3 years, and most patients (84%) were male. The mean left ventricular ejection fraction (LVEF) was 13.7 ± 6.8%, with 58% of patients with EF 10% or less. The etiology was acute decompensated heart failure in 14 patients and acute myocardial infarction in 5 patients. The average duration of Impella 5.5/5.0 support was 12.5 days (1, 40). Six patients (32%) had the device for more than 14 days. Four patients had Impella CP placed prior to 5.5 for 4.75 days (1,8), and two patients required support with extracorporeal membrane oxygenation (ECMO), both after CP but prior to 5.0. Seven patients (37%) were successfully bridged to either left ventricular assist device (LVAD) or heart transplantation on average of 13 ± 10.8 days after Impella insertion with 43% (6/14) of the 5.5 cohort, and 20% (1/5) of the 5.0 cohort. Overall survival rate was 32% (6/19) with rate of 36% (5/14) for Impella 5.5 and 20% (1/5) for Impella 5.0<b>.</b> Overall hemolysis rate was 47%, with 60% (3/5) in the 5.0 cohort and 43% (6/14) in the 5.5 cohort. Other complications included significant upper extremity neuropathy (1), improper positioning (6), hematoma (3), thrombus (1), and stroke (3). <h3>Conclusion</h3> : There is high mortality associated with cardiogenic shock. The Impella 5.0 and 5.5 can provide additional cardiac support and help with bridging to LVAD or heart transplantation. About a third of the patients were successfully bridged, but serious complications do occur with extended support, including hemolysis, hematoma, thrombus, and stroke. Six patients survived to discharge.