Clinical characteristics and short-term outcomes in patients with cardiogenic shock undergoing mechanical circulatory support escalation from intra-aortic balloon pump to impella: From the J-PVAD registry

Background: An escalation strategy from intra-aortic balloon pump (IABP) to Impella (AbioMed, Danvers, MA, USA) is proposed in patients with cardiogenic shock (CS) refractory to IABP therapy, but its clinical data are lacking. This study aimed to elucidate the clinical characteristics and short-term outcomes in patients undergoing IABP-Impella escalation.

Methods and results: From the Japanese nationwide registry of Impella (J-PVAD), a total of 2578 patients with CS receiving Impella support were classified into the IABP-Impella group (n = 189) or the Primary Impella group (n = 2389). We applied 1:3 propensity score (PS) matching, selecting 185 patients and 555 patients, respectively. Before matching, the IABP-Impella group presented longer shock-to-Impella time, worse laboratory data, and more frequent inotropes and pulmonary artery catheter use than the Primary Impella group. After matching, the baseline characteristics were well-balanced. Regarding the 30-day clinical outcomes in the PS-matched cohort, there were no significant differences in the rates of mortality and major complications (a composite of bleeding, hemolysis, infection, stroke, myocardial infarction, limb ischemia, and vascular injury) between the groups. However, The IABP-Impella group showed a significantly higher rate of infection (10.3 % vs. 5.6 %, p = 0.042) and additional mechanical circulatory support use (34.1 % vs. 23.8 %, p = 0.008) than the Primary Impella group.

Conclusions: Compared to patients with primary Impella support, those undergoing IABP-Impella escalation showed similar 30-day mortality and major complications despite poorer clinical conditions before Impella support and a more complicated clinical course after Impella insertion.