Trends in clinical outcomes of Impella support in patients with acute myocardial infarction complicated by cardiogenic shock in japan: insights from the J-PVAD

Background The microaxial flow pump Impella was introduced in Japan in 2017. Although it has been primarily used in patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS), limited data are available on temporal trends in clinical outcomes. Purpose This study aimed to investigate temporal trends in clinical outcomes of Impella support in patients with AMI-CS. Methods The J-PVAD Registry enrolls all consecutive patients who receive Impella support in Japan. We analyzed patients with AMI-CS who underwent successful Impella implantation between 2020 and 2023. Temporal trends in clinical outcomes, including complications, the timing of Impella initiation, and mortality were evaluated. Results Among 5,216 patients, Impella use for AMI-CS increased annually (2020: 683; 2021: 1,133; 2022: 1,539; 2023: 1,861, Figure 1A). The median age was 71 years; 81% were men, and 39% received concomitant venoarterial extracorporeal membrane oxygenation, with no temporal differences. The composite complication rate decreased (2020: 45% vs 2023: 38%; p=0.001), with the most pronounced reductions observed in bleeding and hemolysis. The proportion of Impella-supported percutaneous coronary intervention (PCI) increased and bailout use decreased, with a progressive rise in pre-PCI initiation (2020: 48% vs 2023: 59%; p<0.001, Figure 2A). Pre-PCI Impella initiation was associated with lower 30-day mortality than initiation during or after PCI (Figure 2B). Nevertheless, 30-day mortality showed no significant temporal change (2020: 37% vs 2023: 38%; p for trend=0.36, Figure 1A and 1B). Conclusions The use of Impella for AMI-CS increased over time. Best practices improved, including reductions in complication rates and greater use of pre-PCI Impella initiation. However, no significant improvement in overall mortality was observed.Figure 1Figure 2