SHOCK2: Single-center Experience and Outcomes with Impella 5.0 and 5.5 in Patients with Cardiogenic Shock

Background: Over the past decade, there have been significant technological advancements in managing patients with cardiogenic shock (CS). Temporary mechanical circulatory support devices are increasingly being employed. In this study, we present the largest single-center experience with Impella 5.0 and 5.5. Methods: Adults with severe CS who were supported with Impella 5.0 or 5.5 between 2010 to 2022 at a single institution were included. Patients were stratified into 3 groups according to their CS etiology: 1) acute myocardial infarction (AMI), 2) acute heart failure (AHF), and 3) post-cardiotomy (PC). The primary outcome was survival, and secondary outcomes included complications during Impella support. Multivariable logistic regression was performed to identify risk factors of mortality prior to discharge. Results: A total of 126 patients were included in this study with CS secondary to AMI (n=37), AHF (n=79), and PC (n=10). The AMI group tended to have older patients with a higher rate of hypertension. Patients in the PC group had a higher rate of preoperative atrial fibrillation and elevated total bilirubin. Among all the groups, the AHF group had a longer hospital length of stay and Impella support duration. Intra-aortic balloon pump and coronary revascularization were more commonly employed in the AMI group. Impella with extracorporeal membrane oxygenation (ECPella) support was utilized in 32 patients (25.4%) from the entire study cohort (Table 1). Impella bridge to transplant was most common in the AHF group, and native cardiac recovery was the most common destination in the AMI and PC groups (Table 1). Rates of survival on discharge, 30-day, 90-day, and 180-day were comparable among the 3 groups (Table 2). Acute kidney injury was the most common complication during Impella support followed by infection requiring antibiotics in all 3 groups (Table 2). An increased rate of limb ischemia was observed in the PC group, and the AMI group experienced a higher incidence of bleeding requiring transfusion. Multivariable analysis demonstrated diabetes mellitus (OR 4.90, CI 1.89-12.72, p=0.001), elevated pre-insertion serum lactate (OR 1.24, CI 1.06-1.44, p=0.008), and acute kidney injury (OR 4.81, CI 1.31-17.62, p=<0.001) were independent predictors of mortality prior to discharge, but etiology of CS did not impact mortality prior to discharge (all, p>0.05). Conclusions: The present study is the largest single-center experience with Impella 5.0 and 5.5 to date. This study demonstrates that Impella 5.0 and 5.5 provide appropriate therapeutic support for patients with profound CS with more than half of patients being alive at 180 days. Etiology of CS did not significantly impact survival. Additional ECMO support was required in more than a quarter of the cohort. Diabetes mellitus, elevated pre-insertion serum lactate, and acute kidney injury were strong risk factors for mortality prior to discharge.