Main Inclusion Criteria: * Chronic ischemic or non-ischemic cardiomyopathy * NYHA class III/IV * LVEF ≤35% * Guideline-directed medical therapy for heart failure; ICD Main Exclusion Criteria: * Restrictive cardiomyopathy, hypertrophic cardiomyopathy, acute myocarditis, pericardial disease, amyloidosis, infiltrative cardiomyopathy, uncorrected thyroid disease or discrete left ventricular (LV) aneurysm * Prior heart transplantation, left ventricular reduction surgery (LVRS), cardiomyoplasty, passive restraint device (e.g., CorCap™ Cardiac Support Device), mechanical circulatory support device (MCSD) or cardiac shunt * Likely to receive cardiac resynchronization therapy, cardiomyoplasty, LVRS, conventional revascularization procedure or valvular repair in the 6 months following treatment * Likely need for an immediate heart transplant or MCSD implant due to hemodynamic instability * Inadequate hepatic and renal function * Diagnosis of, or treatment for, any cancer within the last 5 years except for basal cell carcinoma or carcinomas in situ where surgical excision was considered curative