Outcomes and Complications Associated with the Impella 5.5 in Cardiogenic Shock

Background : While randomized trial data and multiple observational cohorts have reported outcomes and safety associated with the percutaneous Impella CP in cardiogenic shock (CS; Abiomed, Danvers, MA), there is limited data available on the newer surgically implanted Impella 5.5. Methods : We conducted a retrospective single-center analysis of all patients who received an Impella 5.5 between October 2022 and October 2024. The primary outcome was a composite of native heart recovery or heart replacement therapy. The primary safety outcome was a composite of cerebrovascular events, Bleeding Academic Research Consortium (BARC) ≥3 bleeding, major vascular complication, major hemolysis, device malfunction requiring intervention, and need for new renal replacement therapy (RRT). Results : 116 patients were included with a cumulative total of 1,860 days of Impella 5.5 support. The majority of patients had SCAI stage D or E CS (67.2%), most commonly due to heart failure-CS (69.0%). The primary outcome was achieved in 70.7% and the primary safety outcome occurred in 44.0%, which was most commonly BARC ≥3 bleeding (31.9%) and need for new RRT (12.1%). Major complications occurred at a rate of 0.046 per day of Impella 5.5 support, or approximately one every 22 days. In the absence of a major complication, mortality was 23.1%, which increased to 36.7% with one, and 66.7% with two or more major complications. Conclusions : The Impella 5.5 can bridge a substantial proportion of highly selected patients with CS to a survivable outcome. However, major complications affect nearly half of patients and were closely associated with mortality.