Acute hemodynamic effects after Impella 5.5 in cardiogenic shock and association with clinical outcomes

Cardiogenic shock (CS) is associated with high short-term mortality and the use of temporary mechanical circulatory support (tMCS) devices, especially left-sided microaxial flow pumps (Impella, Abiomed), has increased in recent years. However, few studies have investigated tMCS's effect on right ventricular-pulmonary artery (RV-PA) hemodynamics and its impact on clinical outcomes. We retrospectively analyzed all adult patients implanted with Impella 5.5 at our institution with acute myocardial infarction or acute decompensated heart failure-induced CS between 2019 to 2023. We found that Impella 5.5 led to an early improvement in RV-PA hemodynamics, even in patients with poor baseline RV function. In addition, we found that RV function itself did not predict death, post-heart transplant right ventricular-primary graft dysfunction, or post-left ventricular assist device severe RV failure. However, an increase in right atrial:pulmonary capillary wedge pressure ratio (RA/PCWP) despite tMCS support was a powerful prognosticator. Our study sheds important insight into anticipated hemodynamic changes after Impella 5.5 placement, supports the use of early tMCS even in patients with marginal RV function in the setting of left heart disease, and highlights the importance of serial assessment of RA/PCWP as a key determinant of CS outcomes.