Clinical Research & Data, Safety & Efficacy, AMI Cardiogenic Shock
Influence of Impella® Timing and Predicted Mortality Risk in Cardiogenic Shock
Prof. Andreas Schäfer, MD, discusses results from his recent paper “Influence of Timing and Predicted Risk of Mortality in Impella-Treated Infarct-Related Cardiogenic Shock Patients.” Dr. Schäfer is deputy director of the Clinic for Cardiology & Angiology at Hannover Medical School in Hannover, Germany.
This retrospective registry paper compares individually predicted mortality using CardShock and IABP-SHOCK II scores in 166 AMI-related cardiogenic shock (AMICS) patients from 3 high-volume cardiogenic shock centers in Germany and 1 center in Denmark. Dr. Schäfer explains that in the absence of adequately powered prospective trials to guide the use of mechanical circulatory support (MCS) devices in AMICS patients, “The best way to approach and compare to at least some of the prospective trials was to focus on patients as they were included in the trials, and the big trial being the IABP-SHOCK II trial.” Thus, he explains that they chose patients from local registries who met the inclusion and exclusion criteria for the IABP-SHOCK II trial.
Patients were treated with the Impella 2.5® or Impella CP® heart pump to determine whether standardized use of Impella in AMICS is associated with lower than predicted mortality rates, and whether timing of implantation or selecting patients based on predicted risk is meaningful.
Dr. Schäfer speaks to the impact of support when patients were stratified according to low, intermediate, and high-risk; according to timing of Impella use (pre- or post-Impella); and according to the occurrence of cardiac arrest prior to support. With regard to the latter, he explains that a majority of AMICS patients supported with Impella in this paper had been resuscitated prior to arrival in the hospital, stating, “not surprisingly, patients with cardiac arrest prior to implementation of the device had worse outcomes.”
Dr. Schäfer also speaks to the multivariate analysis of 12-day and 30-day mortality, as well as differences in results and conclusions in this paper compared to another German paper by Schrage et al. He highlights that while his paper calculated each patient’s predicted risk individually, Schrage et al. used a matched pair analysis leading to differences in baseline patient characteristics and much sicker patients (lower left ventricular function at presentation and higher lactate levels) in Dr. Schäfer’s paper.
Dr. Schäfer’s paper concludes that observed mortality on circulatory support with an Impella was significantly lower than predicted in patients with highest mortality risk. Implantation prior to PCI in acute myocardial infarction-related cardiogenic shock seemed to be associated with lower mortality than implantation post-PCI.