Association of Use of an Intravascular Microaxial Left Ventricular Assist Device vs Intra-aortic Balloon Pump With In-Hospital Mortality and Major Bleeding Among Patients With Acute Myocardial Infarction Complicated by Cardiogenic Shock

Influence of Timing and Predicted Risk on Mortality in Impella-Treated Infarct-Related Cardiogenic Shock Patients

Background: In-hospital mortality in acute myocardial infarction-related cardiogenic shock (AMI-CS) remains high. The only adequately powered randomized trial showed no benefit of routine use of the intra-aortic balloon pump in AMI-CS. We compared individually predicted mortality using CardShock- and IABP-Shock II-scores in AMI-CS patients treated with an Impella microaxial pump, who met the IABP-Shock II-trials inclusion/exclusion criteria, to observed mortality on circulatory support in order to determine whether standardized use of an Impella microaxial flow-pump in AMI-CS is associated with lower than predicted mortality rates and whether timing of implantation or selecting patients based on predicted risk is meaningful.

Methods and Results: We analyzed data from 166 consecutive Impella-treated AMI-CS patients meeting the inclusion/exclusion criteria of the IABP-Shock II-trial (age 64 ± 11 years). Thirty-nine percentage of 64 patients had been resuscitated before Impella implantation. Overall 30-day mortality was 42%. Mortality was higher in resuscitated patients (50 vs. 36%, p = 0.0452) and when Impella was implanted post-PCI (Impella-pre-PCI: 28%, Impella-post-PCI: 51%, p = 0.0039). While in both score systems there was no significant difference between predicted and observed overall 30-day mortality, predicted mortality was significantly higher than observed mortality on Impella support only for individuals with highest predicted risk based on CardShock score (predicted 77 vs. observed 51%, p = 0.025).

Conclusions: Our retrospective analysis suggests that the use of the Impella microaxial pump may be effective in selected cases of high risk patients with AMI-CS.

Condensed abstract: Mortality is high in acute myocardial infarction-related cardiogenic shock despite rapid revascularization. Haemodynamic support with an intraortic balloon pump does not reduce mortality. In this retrospective registry including 166 consecutive IABP-Shock II-eligible cardiogenic shock patients in four dedicated shock centers, 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.

Contrast-induced acute kidney injury

Although major advancements in the field of cardiology have allowed for an increasing number of patients to undergo minimally invasive imaging and interventional procedures, contrast-induced acute kidney injury (CI-AKI) continues to be a dreaded complication among patients receiving intravascular contrast media. CI-AKI is characterized by progressive decline in kidney function within a few days of contrast medium administration. Physiological changes resulting from the direct nephrotoxic effect of contrast media on tubular epithelial cells and release of vasoactive molecules have been implicated in creating a state of increased oxidative stress and subsequent ischemic renal cell injury. Over the last several years, preventive strategies involving intravenous hydration, pharmaceutical agents and renal replacement therapies have resulted in lower rates of CI-AKI. However, due to the evolving paradigm of diagnostic and therapeutic interventions, several unanswered questions remain. This review highlights the epidemiology, pathogenesis and preventive strategies of CI-AKI.

Patient Characteristics, Treatment and Outcome in Non-Ischemic vs. Ischemic Cardiogenic Shock

Aim: Evidence on non-ischemic cardiogenic shock (CS) is scarce. The aim of this study was to investigate differences in patient characteristics, use of treatments and outcomes in patients with non-ischemic vs. ischemic CS. Methods: Patients with CS admitted between October 2009 and October 2017 were identified and stratified as non-ischemic/ischemic CS based on the absence/presence of acute myocardial infarction. Logistic/Cox regression models were fitted to investigate the association between non-ischemic CS and patient characteristics, use of treatments and 30-day in-hospital mortality. Results: A total of 978 patients were enrolled in this study; median age was 70 (interquartile range 58, 79) years and 70% were male. Of these, 505 patients (52%) had non-ischemic CS. Patients with non-ischemic CS were more likely to be younger and female; were less likely to be active smokers, to have diabetes or decreased renal function, but more likely to have a history of myocardial infarction; and they were more likely to present with unfavorable hemodynamics and with mechanical ventilation. Regarding treatments, patients with non-ischemic CS were more likely to be treated with catecholamines, but less likely to be treated with extracorporeal membrane oxygenation or percutaneous left-ventricular assist devices. After adjustment for multiple relevant confounders, non-ischemic CS was associated with a significant increase in the risk of 30-day in-hospital mortality (hazard ratio 1.14, 95% confidence interval 1.04–1.24, p < 0.01). Conclusion: In this large study, non-ischemic CS accounted for more than 50% of all CS cases. Non-ischemic CS was not only associated with relevant differences in patient characteristics and use of treatments, but also with a worse prognosis. These findings highlight the need for effective treatment strategies for patients with non-ischemic CS.