Comparison of in-hospital outcomes of ST-elevation myocardial infarction patients with cardiogenic shock receiving left ventricular mechanical circulatory support devices based on transfer status

Background

We aimed to compare outcomes in patients who receive on-site left ventricular mechanical support versus those transferred to other facilities for mechanical support in ST-elevation myocardial infarction (STEMI) patients with cardiogenic shock.

Methods

This retrospective study analyzed data from the 2016 to 2020 Nationwide Inpatient Sample (NIS) database. We identified patients with STEMI and cardiogenic shock who received Impella and LVAD placement during their hospital stay. They were divided into two groups: those with in-house (direct) placement and those transferred to higher-level medical centers. The primary goal was to compare mortality rates between these groups.

Results

During the study, 15,934 (75.2%) received in-house left ventricular support, while 5255 (24.8%) were transferred. Mean age (63 vs. 64 years) and female percentage (25 vs. 26%) were similar. The average time from admission to receiving LV support was 0.8 days for direct group versus 2.8 days for transfer group (p < 0.001). Transferred patients had a higher rate of prior heart failure (68 vs. 79%, p < 0.001) and peripheral vascular disease (10 vs. 14%, p < 0.001) but a lower rate of hypertension (23 vs. 17%, p = 0.003). There were no significant differences in other comorbidities. Primary outcome mortality did not significantly differ (44.9 vs. 44.2, p = 0.66). After multivariate analysis, transferred patients had higher rates of ECMO usage, acute kidney injury, renal replacement therapy, major bleeding, and ischemic stroke. Length of stay (8 vs. 15 days, p < 0.001) and total charges ($391,472 vs. $581,183, p < 0.001) were significantly higher in the transferred group.

Conclusion

Among STEMI patients with cardiogenic shock, our study found no significant difference in mortality between patients transferred for and those with on-site LV support. Those transferred patients experienced more complications, longer length of stay, and increased hospital costs.