Inclusion Criteria:  Severe clinical HF resistant to intensive medical therapy and requiring LVAD implantation Left ventricular ejection fraction <=25% and cardiomegaly at time of LVAD implantation Non-ischemic etiology of HF Undergone LVAD implantation within prior 4 weeks or planned for LVAD implant History of HF < 5 years Body Mass Index <=35 kg/m^2 Pulmonary artery branch diameter between 7 - 15 mm Female subjects of childbearing age with negative urine or serum pregnancy test and agreeing to use reliable mechanical or hormonal form of contraception during study  Exclusion Criteria:  Evidence of active acute myocarditis confirmed by histology History of previous cerebrovascular accident resulting in significant fixed motor deficit, limiting ability to perform exercise testing Implanted mechanical aortic and/or mitral valve(s) and/or right heart valve(s) Aortic valve closure Hypertrophic obstructive cardiomyopathy or sarcoidosis Left ventricular end-diastolic diameter below normal (restrictive cardiomyopathy) Irreversible multi-organ failure Diagnosis of psychiatric disease, irreversible cognitive dysfunction or poor psycho-social issues likely to impair compliance with study protocol Any condition that could limit survival to less than 2 years History of cardiac or other organ transplant Contraindicated to anti-coagulation, antiplatelet therapy, or diagnosis of coagulation disorders Require acute or chronic renal replacement therapy within 3 months prior to enrollment Participation in any other clinical investigations involving another Mechanical Circulating Support device or HF-related drug Active infection History of recurrent (>1) pulmonary embolism or deep vein thrombosis Unable to tolerate right heart catheterization Implantation of cardiac re-synchronization therapy < 3 months before enrollment Congenital heart disease Hypersensitivity or allergy to aspirin and/or clopidogrel