First results of the 'Deutsches Herzzentrum der Charite' paediatric impella cohort.

Objectives: Mechanical support options for children and small adolescents in low cardiac output syndrome or cardiogenic shock are often still limited to veno arterial extracorporeal life support and subsequent left or biventricular assist device implantation. We aim to transfer mechanical support options with microaxial flow pump devices from the adult to the paediatric population and therefore aim to identify patient selection criteria and evaluate possible support duration and bridging modalities in a paediatric Impella registry.

Methods: This is a single-centre retrospective observational study including every patient <18 years presenting with cardiogenic shock and treated with an Impella device only from 2022 to 2024.

Results: The study cohort included 6 patients with a median age of 12 (3-17 years), median weight of 35.6 kg (12-115 kg) and a median body surface area (BSA) of 1.2 m2 (0.57-2.4 m2). Intermacs levels were 2 (4 patients) and 3 (2 patients). Heart failure aetiologies were dilative cardiomyopathy (3 patients), myocarditis (1 patient), acute rejection after cardiac transplantation (1 patient) and low cardiac output syndrome after complex endocarditis surgery (1 patient). The implanted devices were an Impella 2.5 [1], Impella CP [2] and Impella 5.5 [3]. Median support duration was 7 (4-45) days. Two patients could be bridged to recovery. Three patients were bridged to an left ventricular assist device, and 1 patient was bridged to cardiac transplantation. We observed no mortality and no neurological complications.

Conclusions: Left ventricular unloading in cardiogenic shock in children and adolescents using an Impella is feasible and safe. In older patients allowing for implantation of larger devices, a longer support duration is possible.