Post-Market Approval Experience with Impella 5.5 Trans-Aortic Valve Axial Flow Pump

Abstract

<h3>Purpose</h3> Impella 5.5 is trans-aortic valve axial flow pump that provides over 6 L/min of blood flow. It received U.S. FDA approval in late 2019 to support cardiogenic shock (CS) patients up to 14 days. We present our initial clinical experience <h3>Methods</h3> A retrospective review of CS patients receiving Impella 5.5 support over 18 months. Patient data included demographics, comorbidities, INTERMACS profile, SAVE score, patient and device complications, transition to long-term support or heart transplant, time of follow-up, and mortality rates. Multiple Kaplan-Meier survival analyses were based on age, CS status (INTRMACS and SAVE scores), body mass index (BMI), and time of follow-up. A t-test for two-samples was performed to establish statistical differences between age groups (<65 and >65 years), BMI groups (<30 and >30kg/m2), and transition of cardiac support and/or transplant. Finally, an ANOVA for single factor analysis was done for the different SAVE scores present (Class III, IV, and V). <h3>Results</h3> A total of 32 patients were predominantly white (91%) males (78%) with an average age and BMI of 58.7±17.6 years and 28.6±6.8 kg/m², respectively. Most patients presented decompensated cardiogenic shock (INTERMACS I) at time of implant. 11 patients (34%) were bridged to heart transplant, 10 (31%) were upgraded to VA ECMO, and 5 to bi-ventricular Impella (16%). Patient /device complication rate was 25%. While age and transition groups showed no difference in survival rates (<i>p</i>=0.07 and <i>p</i>=0.3, respectively; CI 95%) patients with a BMI <30 kg/m² showed better survival rates following intervention (<i>p</i><0.01; CI: 95%). There was no difference between SAVE score groups III, IV, and V (p=0.5; CI:95%). 15 (47%) patients received physical therapy (5.5 ± 6.3 sessions / patient), with 13 (87%) of them progressing to heart transplantation. <h3>Conclusion</h3> Impella 5.5 provided robust hemodynamic support for patients with severe cardiogenic shock, with over 50% hospital survival, including a third of patients bridged to heart transplant.