Clinical features and outcomes in patients with cardiogenic shock complicating acute myocardial infarction: early vs recent experience with impella.

OBJECTIVES: To compare clinical features and outcomes in patients with acute myocardial infarction complicated by cardiogenic shock (AMICS) treated in the early experience with Impella percutaneous ventricular assist device and patients treated recently. BACKGROUND: Since pre-market approval (PMA) of Impella device as treatment for AMICS, use of the device has grown considerably. METHODS: We retrospectively analyzed 649 AMICS patients treated with perioperative Impella, with 291 patients treated from 2008 to 2014 comprising the early experience cohort and 358 patients treated from 2017 to 2019 comprising the recent experience cohort. The primary end point was risk adjusted in-hospital mortality. RESULTS: Mean age and gender distribution of patients was similar in the two cohorts. The recent cohort had more invasive hemodynamic monitoring (64% vs 46%; P < .001) and less use of an intra-aortic balloon pump prior to Impella (15% vs 41%; P < .001). Recently treated patients were significantly more likely to receive Impella support prior to PCI (58% vs 44%; P = .005). In-hospital mortality was lower in the recent cohort (48% vs 56%; P = .043). This difference was however no longer significant after risk adjustment (adjusted OR 0.89, 95% CI 0.59-1.34, P = .59). Rates of acute kidney injury, major bleeding, and vascular complications requiring surgery were also significantly lower in the recent cohort. CONCLUSIONS: Use of Impella for AMICS during recent years is associated with lower unadjusted in-hospital mortality, which may reflect better patient selection, earlier device implantation, and improved management algorithms. In-depth understanding of these factors may inform the development of future treatment protocols.