Early mobilization trajectories during Impella 5.5 support and associated outcomes in patients with cardiogenic shock: A physiotherapy session-level analysis.

BACKGROUND: Catheter-based micro-axial flow pump, Impella, has improved patient prognosis following cardiogenic shock (CS). Notably, Impella 5.5 facilitates patient activity because of the cannulation approaches to the axillary artery. OBJECTIVES: To characterize mobility level trajectory and its safety and association with prognosis in patients with CS during Impella 5.5 support using detailed physiotherapy session-level data. METHODS: We reviewed consecutive patients with CS who underwent early physiotherapy during Impella 5.5 in intensive care unit (ICU) from 2022 to 2025. Mobility level was assessed using the ICU Mobility Scale (IMS) as a primary endpoint and adverse events leading to the termination of physiotherapy were recorded during each session. The successful weaning from Impella, bridge to implantable left-ventricular assist device (iLVAD), or death while or after Impella weaning were investigated as patient prognosis. RESULTS: A total of 876 physiotherapy sessions among 30 patients were included for analysis with 550 sessions (63.3%) of out-of-bed mobilization. Forty-three events on Impella device alarm (4.9%) and 91 on decreased arterial pressure (10.4%) were observed; however, no life-threatening events occurred during physiotherapy. Overall, IMS significantly increased over time after adjustment for confounders (P < 0.001). Patients successfully weaned from Impella 5.5 showed more favorable IMS trajectories than those bridged to iLVAD, those with failure to wean, and those who died after Impella weaning (interaction P = 0.064, 0.002, and 0.015, respectively). CONCLUSIONS: Early mobilization levels increased progressively after Impella 5.5 implantation without severe adverse events. More favorable mobility trajectories were associated with better prognosis in patients with CS.