Microaxial flow pump in cardiogenic shock: a retrospective cohort study on outcomes and feasibility as a bridge to LVAD implantation.

Introduction: In severe cardiogenic shock the use of temporary mechanical circulatory support has increased during the past decade, with the Impella CP emerging as an alternative to the intra-aortic balloon pump. This study aims to assess the clinical outcomes associated with Impella CP-only support in patients with cardiogenic shock within two tertiary institutions specialised in durable mechanical support in the Netherlands.

Methods: All patients receiving Impella CP implantation for cardiogenic shock in the UMC Utrecht and UMC Groningen were studied between December 2020 and August 2023. Exclusion criteria included the use of additional mechanical support. The primary outcome evaluated was 30-day mortality. Secondary outcomes included LVAD implantations, cardiac recovery, and safety outcomes. Patients were categorised as Impella-optimal (Impella support expected to be sufficient) or Impella-limited (Impella support not sufficient but no further escalation because of comorbidities).

Results: The cohort consisted of 28 patients. The mean age was 60 years, and 71% were males. In the Impella-limited group, mortality was 100%, and LVAD implantation was performed in just 10%, while in the Impella-optimal group, mortality was 17% and LVAD implantation was performed in 50%. Complications were primarily related to bleeding (7%) and vascular events (11%).

Conclusions: This study suggests that Impella CP support in cardiogenic shock can be safe and feasible, serving as a bridge-to-recovery or a bridge-to-decision for LVAD implantation candidacy. However, Impella CP in the Impella-limited group is not useful. This underscores the importance of precise patient selection in cardiogenic shock therapy escalation.