Abstract Body (Do not enter title and authors here): Introduction: Cardiogenic shock (CS) remains a clinical challenge with a high mortality rate. An escalation strategy from intra-aortic balloon pump (IABP) to Impella has been proposed for patients with CS refractory to IABP therapy, but clinical data on this approach are lacking. This study aimed to elucidate the short-term clinical outcomes after IABP-Impella escalation in patients with CS.
Methods and Results:
From the Japanese nationwide registry of Impella (J-PVAD) database between 2020 and 2022, a total of 2,578 patients with CS who received Impella support were classified into the IABP-Impella group (n=189) or the Primary Impella group (n=2,389). We applied a 1:3 propensity score matching, selecting 180 patients in the IABP-Impella group and 540 patients in the Primary Impella group. Before matching, the IABP-Impella group presented significantly longer shock-to-Impella time, worse laboratory data indicating multiorgan damage, and more frequent inotrope use compared to the Primary Impella group. After matching, the baseline characteristics were well-balanced between the two groups. The clinical outcomes within 30 days after the initiation of Impella were compared between the matched groups. The IABP-Impella group showed a significantly higher rate of additional mechanical circulatory support (MCS) use than the Primary Impella group (33.9% vs. 25.6%, p=0.034). Although the incidence of mortality was similar between the two groups (30.6% vs. 30.9%, p>0.99), the incidence of major complications (a composite of bleeding, hemolysis, infection, stroke, myocardial infarction, limb ischemia, and vascular injury) tended to be higher in the IABP-Impella group (43.0% vs. 36.3%, p=0.053). Notably, the incidence of infection was significantly higher in the IABP-Impella group than in the Primary Impella group (10.0% vs. 4.8%, p=0.018). Kaplan-Meier estimates revealed that infection occurred more frequently in the IABP-Impella group during the 30-day follow-up period (log-rank p=0.016).
Conclusions: Patients undergoing the IABP-Impella escalation strategy showed poorer baseline clinical conditions in baseline and were associated with a higher likelihood of further MCS upgrade and an increased risk of infection.