Clinical outcomes of axillary-implanted impella 5.0/5.5 for ischemic cardiogenic shock: a retrospective single-center cohort study

Cardiogenic shock (CS) is a leading complication of acute myocardial infarction (AMI), accounting for significant mortality and morbidity. Temporary mechanical circulatory support (t-MCS) has recently emerged as a valuable option for CS treatment, also serving as a crucial backup for high-risk percutaneous coronary interventions (PCI). DanGer Shock Trial was the first to show the superiority of Impella CP over standard-of-care treatment in this setting. The role of Impella 5.0/5.5 in such a complex framework is much less investigated, despite its theoretical potential to offer higher hemodynamic support.

This study aims at providing insights into the clinical outcomes of a cohort of AMI-related CS patients supported with Impella 5.0/5.5.

This single-center, retrospective study analyzed in-hospital clinical outcomes of AMI-related CS patients supported with Impella 5.5/5.0. Data were retrospectively collected using an electronic medical record system and ALT-Shock registry and are reported as mean or percentage values.

Between January 2022 to May 2024, 28 patients were implanted with Impella 5.0/5.5. Mean age was 72 ± 8.9 years and 96% were male. At admission 11 (39%) of patients were classified as SCAI C, 11 (39%) as SCAI D and 6 (32%) as SCAI E. Mean left ventricular (LV) ejection fraction (EF) at admission was 15% (± 7,7), with 50% of patients presenting with severe mitral regurgitation. 11 (39%) patients required ECMO support due to further deterioration and subsequent unloading with Impella 5.0/5.5 implantation. Intra-aortic balloon pump (IABP) escalation was necessary in 19 (67%) patients. PCI was performed in 26 patients, with 12 (16%) of which having multivessel disease requiring revascularization during ongoing support. Mean duration of support was 7,5 ± 10,5 days, with a maximum duration of 50 days; bleeding complications occurred in 2 (7%) patients. Overall survival rate during index hospitalization was 78%: 3 patients (14%) were bridged to durable LVAD and 2 patients (9%) underwent heart transplantation (HTX), both of whom experienced severe CS with right ventricular (RV) dysfunction necessitating ECMO support. At discharge, 17 (77%) patients achieved a median ejection fraction of 33%.

In our experience, the enhanced power and durability of Impella 5.0/5.5 provide a high probability of survival and myocardial recovery in AMI-related CS patients, with a low incidence of complications and organ injury. By unloading left ventricle and reducing myocardial oxygen demand, Impella 5+ played a crucial role in our cohort. Moreover, the low bridge-to-transplant rate, even among those requiring ECMO, suggests the importance of effective unloading in critically ill patients. Nevertheless, further prospective data are still warranted.