Trends and outcomes of different mechanical circulatory support modalities for acute myocardial infarction associated cardiogenic shock in patients undergoing early revascularization

Background

The use of Mechanical Circulatory Support (MCS) devices in cardiogenic shock (CS) is growing. However, the recent trends in using different MCS modalities and their outcomes in acute myocardial infarction associated CS (AMI-CS) are unknown.

Methods

The national readmission database (2016–2020) was used to identify AMI-CS requiring MCS. Cohorts were stratified as ECMO compared to Impella. Propensity score matching (PSM) was used to remove confounding factors. Pearson's x2 test was applied to matched cohorts to compare outcomes. We used multivariate regression and reported predictive margins for adjusted trend analysis.

Results

Among 20,950 AMI-CS hospitalizations requiring MCS, 19,628 (93.7 %) received Impella vs 1322 (6.3 %) were placed only on ECMO. ECMO group was younger (median age: 61 vs. 68 years, p < 0.001) and had a lower comorbidity burden. On propensity-matched cohorts (N 742), the ECMO cohort had higher adverse events, including mortality (51.6 % vs. 41.5 %), sudden cardiac arrest (SCA) (40.9 % vs. 31.8 %), acute stroke (9.2 % vs. 4.6 %) and major bleeding (16 % vs 12.2 %) [p < 0.05]. However, comparing ECPELLA (ECMO + Impella) to Impella alone, mortality (46.2 % vs. 39.4 %) and SCA (44 % vs. 36.4 %) rates were similar, though major bleeding was higher (18.2 % vs. 9.8 %). From 2016 to 2020, mortality trends for AMI-CS in the U.S. showed no significant change (p-trend: 0.071).

Conclusion

Despite advances in MCS modalities, the overall mortality rate for AMI-CS remains unchanged. ECMO use without LV unloading showed higher mortality and adverse events compared to Impella. Prospective studies are needed to verify these findings.