Feasibility Study of the Intravascular Ventricular Assist System (iVAS)

Main Inclusion Criteria: 1. At least 18 years of age. 2. If female, are postmenopausal or surgically sterilized, or have a negative pregnancy test within seven (7) days of invasive testing. 3. Advanced heart failure (NYHA Class III or IV) Main Exclusion Criteria: 1. Hypotension treated with the following medications: epinephrine, norepinephrine, vasopressin, methylene blue, phenylephrine, or angiotensin II. 2. Receiving more than two inotropes. 3. Subclavian stenosis or stent. 4. Currently receiving circulatory support including ECMO, Impella, TandemLife or equivalents; or any durable VAD. 5. Atrial fibrillation without ventricular pacing. 6. Concomitant, non-cardiac disease process with life expectancy \< 1 year. 7. Significant abnormalities of the aorta, such as aneurysms, coarctation of the aorta, or an extremely tortuous aorta. 8. Severe end-organ dysfunction or failure. 9. Any other condition the heart team believes inappropriate for this study.