Impella versus intra-aortic balloon pump in resuscitated out-of-hospital cardiac arrest patients with coronary artery disease

Background The DanGer Shock trial demonstrated a survival benefit with routine Impella use in patients with ST-segment elevation myocardial infarction complicated by cardiogenic shock. However, resuscitated cardiac arrest patients were excluded from that study, and the clinical impact of Impella in this high-risk population remains uncertain. Out-of-hospital cardiac arrest (OHCA) secondary to acute coronary artery disease (CAD) is frequently associated with profound hemodynamic instability, large infarct burden, and poor neurological outcomes. Although mechanical circulatory support (MCS) is often used in this setting, comparative data between Impella and intra-aortic balloon pump (IABP) in resuscitated OHCA patients are limited. We therefore evaluated the clinical impact of Impella compared with IABP in successfully resuscitated OHCA patients with CAD. Methods In this retrospective single-center cohort study, 3,578 consecutive OHCA patients transferred to our critical care center between January 2015 and December 2023 were screened. Seventy-nine patients who achieved return of spontaneous circulation and had obstructive CAD confirmed by coronary angiography were included. Patients received either Impella or IABP support at the discretion of the treating physicians. Baseline characteristics, prehospital variables including witnessed arrest and bystander resuscitation, initial arrest rhythm, electrocardiographic findings, angiographic characteristics, duration of ECMO and MCS support, MCS-related complications, infarct size assessed by peak CK-MB, and survival and favorable neurological outcomes at 30 days and 1 year were analyzed. Neurological status was evaluated using the cerebral performance category (CPC) scale. Results Nineteen patients (24.1%) received Impella and 60 (75.9%) received IABP. There were no significant differences in baseline characteristics, cardiovascular risk profiles, quality of resuscitation, initial arrest rhythm, or presence of ST-segment elevation. Angiographic findings and the duration of ECMO, Impella, and IABP use were comparable between groups. The incidence of MCS-related complications—including bleeding, hemolysis, lower limb ischemia, and acute kidney injury—did not differ significantly. Infarct size assessed by peak CK-MB tended to be lower in the Impella group (median 133.0 vs. 336.5 U/L; p=0.064). Survival rates and favorable neurological outcomes (CPC 1–2) at 30 days and 1 year were similar between groups. Conclusions In successfully resuscitated OHCA patients with CAD, Impella support was not associated with improved survival or neurological recovery compared with IABP. Nevertheless, a signal toward smaller infarct size was observed with Impella. Given the limited sample size and retrospective design, larger prospective studies are warranted to clarify the role of Impella in resuscitated cardiac arrest patients.