162 - DANGER SHOCK IN CONTEXT: AN UPDATED META-ANALYSIS OF IMPELLA PERCUTANEOUS MECHANICAL CIRCULATORY SUPPORT IN ACUTE MYOCARDIAL INFARCTION ASSOCIATED CARDIOGENIC SHOCK

Background: Cardiogenic shock (CS) continues to be a significant cause of morbidity and mortality among patients experiencing acute myocardial infarction (AMI) despite prompt coronary revascularization, with mortality rates for individuals with AMI-CS ranging 30-50%. The recently published DanGer Shock Trial has, for the first time, shown a mortality advantage of early Impella percutaneous mechanical circulatory support (pMCS) in AMI-CS, albeit with a limited sample size. The results of DanGer must therefore be interpreted in the context of other existing evidence.

METHODS AND RESULTS: We updated our previous meta-analysis, originally published in 2022, comparing pMCS to standard medical care in cases of AMI-CS. Apart from the DanGer Shock trial, no other original studies assessing pMCS in the context of AMI-CS meeting our selection criteria has been published since. We performed a random-effects pooled analysis examining both in-hospital and 30-day mortality rates, as well as major bleeding events (defined as BARC≥3).

Including the DanGer Shock trial, five references meeting our selection critera have compared the effect of Impella support to conventional therapy alone in the management of patients suffering from AMI-CS. Among these, three studies demonstrated a significant improvement in mortality with the Impella device, with DanGer Shock being the largest among them, while the other two much larger studies did not show an improvement. Meta-analysis of the included studies did not reveal a significant mortality benefit with Impella use (pooled odds ratio [OR] 0.64; 95% CI 0.34-1.22). Notably, there was a high degree of heterogeneity (I2 = 0.81), suggesting potential variations in patient populations and/or methodological differences between studies. It must be noted that DanGer Shock was the only prospective randomized trial among the references and showed a mortality benefit at 6 months follow-up, but not at 30 dasy. Most other references only reported mortality up to hospital discharge or 30 days. Of the 5 references, three reported on bleeding complications and consistently showed an increase in BARC≥3 bleeding (pooled OR of 3.28; 95% CI 1.8-5.98).


Conclusion: While the DanGer Shock trial showed a mortality benefit of early implementation of Impella support in AMI-CS, the efficacy of pMCS in AMI-CS necessitates further validation when considering other existing evidence, particularly given the increased risk of device-related and other complications in this population. Future studies must examine mortality at 6-12 months in order to fully capture all the downstream effects of early pMCS use.