Comparison of clinical outcomes of acute myocardial infarction patients complicated with cardiogenic shock treated with intra-aortic balloon pump versus microaxial flow pump.

BACKGROUND: The Danish-German (DanGer) Shock trial demonstrated that the use of a microaxial flow pump (Impella) reduced mortality compared to medical management in patients with acute ST elevation myocardial infarction complicated with cardiogenic shock (STEMI-CS). However, patients in the control arm of the DanGer Shock trial were not treated with an intra-aortic balloon pump (IABP), and data directly comparing Impella to IABP in this population is limited.

METHODS: We identified STEMI-CS patients treated with percutaneous coronary intervention (PCI) and IABP at our institution between January 1, 2013, and February 20, 2025. These patients were screened according to the selection criteria of the DanGer Shock trial and were compared to the Impella MCS device 2.5 or CP and standard-of-medical-care (SoMC) arms of the DanGer Shock trial.

RESULTS: Our cohort included 102 STEMI-CS patients treated with IABP. Compared to Impella CP patients from the DanGer Shock trial, IABP patients had significantly higher rates of hypertension, diabetes mellitus, heart failure, and SCAI stage E cardiogenic shock, but significantly lower rates of mechanical ventilation, vasopressor, and inotrope use. At 180 days, IABP patients had similar all-cause mortality compared to Impella CP patients (35.9 % vs. 45.8 %, p = 0.06), and lower rates of major bleeding (6 % vs. 39 %, p < 0.001) and renal replacement therapy (8 % vs. 75 %, p < 0.001). Additionally, IABP patients had lower mortality compared to SoMC patients (35.9 % vs. 58.5 %, p = 0.0004).

CONCLUSION: These findings support the hypothesis that STEMI-CS patients treated with IABP have comparable 180-day mortality to those treated with Impella CP and lower mortality than those receiving standard medical care. STEMI-CS cohort is heterogenous and IABP use may be beneficial in certain patients. Well-designed randomized trials comparing Impella CP and IABP in this patient population are warranted to inform clinical decision-making.

CONDENSED ABSTRACT: Acute ST elevation myocardial infarction complicated with cardiogenic shock (STEMI-CS) portends a high mortality risk. New American guidelines now recommend a peripherally inserted left ventricular assist device, such as Impella, as a Class II indication for the management of STEMI-CS patients. Further, guidelines now give intra-aortic balloon pump (IABP) as a class III indication for these patients. However, there is a need of direct head-to-head comparison of these two mechanical support modalities in this specific subset of patients. In this analysis, we identified STEMI-CS patients treated with IABP at our institution and compared them to the Impella CP cohort from the DanGer Shock trial. We found that both modalities had similar mortality rates, and IABP has lower mortality rates when compared to standard medical cohort from the trial. However, despite applying DanGer Shock selection criteria, group differences exists. The complications rate was lower with IABP as compared to Impella CP. These findings support the use of IABP in the management of certain STEMI-CS patients and its clinical utility should not be underestimated.