Percutaneous ventricular assist devices (pVAD) decrease mortality in cardiogenic shock (CS) patients, but at a high adverse event rate. Novel pVADs need to improve cardiac power output (CPO) to improve efficacy and reduce profile to reduce adverse events. Venstramedical has developed an impeller with nitinol and polymer which can collapse for low-profile insertion and expand in the body to provide optimal CPO. We have also developed a unique 9 French (9Fr) delivery system. In vitro and in vivo testing have been performed to develop this device. Head-flow (HQ) tests generate 5.0 L/min with a pressure differential of 80 mm Hg and 7.0 L/min against 60 mm Hg. Durability testing demonstrated continuous operation of up to 20 days. In the acute healthy ovine model, we demonstrated full flow (7–9 L against 60–80 mm Hg), transcatheter 9Fr delivery, retrieval of the device, and resting of the native heart during pumping. In a CS animal, we demonstrated survival and resting of the native heart during the acute study with decreased stroke work (SW), decreased stroke volume (SV), while total cardiac output was up to 7 L/min and maintaining adequate pressure with low hemolysis. We also demonstrated multiday functioning of the device in a healthy ovine model with good CO and low hemolysis.