Mechanical circulatory support with the Impella® LP5.0 pump and an intra-aortic balloon pump for cardiogenic shock in acute myocardial infarction: The IMPELLA-STIC randomized study

Background. - Percutaneous assist devices may be used as a bridge to recovery in patients with acute myocardial infarction complicated by cardiogenic shock (CS-AMI). Aim. - To test the hypothesis that the Impella (R)` LP5.0 pump (Abiomed Europe GmbH, Aachen, Germany) provides haemodynamic benefits and improves left ventricular ejection fraction (LVEF) in patients with CS-AMI already managed with an intra-aortic balloon pump (IABP). Methods. - This was a prospective randomized study. The primary endpoint was change in cardiac power index (CPI) from baseline to 12 hours after implantation, measured with a Swan-Ganz catheter. Secondary endpoints included LVEF at 30 days. Results. - Fifteen patients with CS-AMI were randomized; 12 were available for primary endpoint analysis (IABP group, n = 6; Impella LP5.0 + IABP group, n = 6). Baseline characteristics were similar in both groups. Change in CPI after 12 hours was not significantly different between the two groups (IABP group: Delta CPI= 0.08 +/- 0.08 W/m(2); Impella LP5.0 + IABP group: Delta CPI = -0.02 +/- 0.25 W/m(2); P= 0.4). There was no significant change from baseline CPI in either group over 96 hours, and no difference in CPI between groups at each timepoint. In the Impella LP5.0 + IABP group, the part of the CPI provided by the native heart decreased from 0.37 +/- 0.10 to 0.10 +/- 0.20 (P= 0.01). LVEF was similar at baseline (29.7% +/- 8.4% and 29.3% +/- 6.7%) and 1 month (40.6% +/- 12.5% and 38.6% +/- 14.4%) in the IABP and Impella LP5.0 + IABP groups, respectively. Adverse events, especially major bleeding, were common, and occurred mainly in the Impella LP5.0 + IABP group. Conclusions. - In patients with CS-AMI stabilized by initial treatment with inotropes and an IABP, the Impella LP5.0 did not provide additional haemodynamic support or improvement in LVEF at 1 month; its use in this setting might be futile and possibly harmful. (C) 2019 Elsevier Masson SAS. All rights reserved.