National Use Patterns and Comparative Effectiveness of Extracorporeal Membrane Oxygenation in Myocardial Infarction-Related Cardiogenic Shock

Extracorporeal membrane oxygenation (ECMO) provides bi-ventricular support for patients with myocardial infarction-related cardiogenic shock (MI-CS); comparative effectiveness data relative to other mechanical circulatory support remain limited. We characterize contemporary ECMO utilization for MI-CS and compare short-term mortality across ECMO and non-ECMO treatment strategies.

We compared baseline characteristics and temporal trends in mechanical circulatory support utilization among Medicare beneficiaries hospitalized with MI-CS from 2016 to 2023 and treated with ECMO, Impella, intra-aortic balloon pump, or medical management alone. Patient outcomes for each group were evaluated using inverse probability of treatment weighting, G-formula approach, and grace period analysis. The primary endpoint was 30-day all-cause mortality.

The cohort included 102 718 patients: 1165 (1.1%) treated with ECMO, 10 064 (9.8%) Impella, 24 631 (24.0%) intra-aortic balloon pump, and 66 858 (65.1%) medical management alone. From 2016 to 2023, ECMO use for MI-CS increased from 0.8% to 1.8%. The percentage of hospitals using ECMO increased from 9.2% to 17.1%. Unadjusted 30-day mortality was higher for ECMO (69%) compared with Impella (60%), intra-aortic balloon pump (39%), and medical management (46%) (all P<0.0001). Adjusted inverse probability of treatment weighting and G-formula analyses revealed a 30-day mortality rate of 68%-70% for ECMO, which was higher than that for other therapies. The grace period analysis revealed similar mortality between patients treated with ECMO (54%) and Impella (54%).

ECMO use in a contemporary Medicare cohort of patients with MI-CS was infrequent (1.1%) and associated with high 30-day mortality. Despite use of complementary causal inference methods, we were unable to establish valid causal inferences on ECMO use and patient survival.