Inclusion Criteria:

• Chronic ischemic or non-ischemic cardiomyopathy. Subjects with ischemic cardiomyopathy must have at least one major coronary vessel with TIMI grade 3 flow.
• Left ventricular ejection fraction (LVEF) ≤35%
• Diagnosis of NYHA Class III/IV heart failure for a minimum of 3 months prior to screening
• Maximal oxygen consumption (VO2 max) ≤20 mL/kg/min within 90 days prior to enrollment
• An implantable cardioverter defibrillator (ICD) implanted a minimum of 30 days prior to enrollment
• Treatment with appropriate heart failure therapy as tolerated
• All women of childbearing potential must have a negative urine pregnancy test prior to administration of investigational product and agree to use adequate contraception. Men capable of fathering a child must agree to use barrier contraception or limit activity to post-menopausal, surgically sterilized, or a contraception-practicing partner, for 3 months after administration of investigational product.
• Ability to sign Informed Consent Form (ICF) and Release of Medical Information Form

Exclusion Criteria:

• Any intravenous therapy with positive inotropes, vasodilators, or diuretics within 30 days prior to enrollment
• Restrictive cardiomyopathy, obstructive cardiomyopathy, pericardial disease, amyloidosis, infiltrative cardiomyopathy, uncorrected thyroid disease, or dyskinetic LV aneurysm
• Cardiac surgery, percutaneous coronary intervention, or valvuloplasty within 30 days prior to enrollment
• Clinically significant myocardial infarction (e.g., ST elevation MI [STEMI] or large non-STEMI) within 6 months prior to enrollment
• Prior heart transplantation, left ventricular reduction surgery (LVRS), cardiomyoplasty, passive restraint device (e.g., CorCap™ Cardiac Support Device), surgically implanted LVAD or cardiac shunt
• Likely to receive cardiac resynchronization therapy, cardiomyoplasty, LVRS, heart transplant, conventional revascularization procedure, or valvular repair within 6 months following enrollment
• Patients with prior coronary artery bypass graft(s) (CABG) will reviewed on a case-by-case basis
• No evidence of functional or viable myocardium
• Exercise capacity primarily limited by obesity, peripheral vascular disease, intrinsic pulmonary disease or orthopedic problems and not by underlying heart failure
• Known hypersensitivity to octafluoropropane (component of the intravenous echocardiography contrast agent, DEFINITY®) or other contrast dyes used for angiography; history of, or likely need for, high dose steroid pretreatment prior to contrast angiography
• A left ventricle that is difficult to image or high quality echocardiography is not obtainable at screening
• Significant left main or ostial right coronary lumenal stenosis in the opinion of the investigator
• Expected survival <1 year in the investigator's medical opinion
• Suspected or active viral, bacterial, fungal, or parasitic infection within 48 hours prior to enrollment
• Liver function tests (ALT, AST, alkaline phosphatase) >2x Upper Limit of Normal (ULN) within 30 days prior to enrollment or known intrinsic liver disease (e.g., cirrhosis, chronic hepatitis B or hepatitis C virus infection)
• Current or likely need for hemodialysis within 12 months following enrollment
• Bleeding diathesis or thrombocytopenia defined as platelet count <50,000 platelets/μL
• Anemia defined as hemoglobin <10 g/dL
• Known AIDS or HIV-positive status, or a previous diagnosis of immunodeficiency with an absolute neutrophil count <1000 cells/mm3
• Previous participation in a study of gene transfer
• Presence of neutralizing anti-AAV1 antibodies at titer ≥1:2 within 3 months of screening
• Receiving investigational intervention or participating in another clinical study within 30 days or within 5 half-lives of the investigational drug administration prior to enrollment
• Pregnancy or lactation
• Recent history of psychiatric disease (including drug or alcohol abuse) that is likely to impair subject's ability to comply with protocol-mandated procedures, in the opinion of the investigator
• Other concurrent medical condition(s) that, while not explicitly excluded by the protocol, could jeopardize the safety of the patient or objectives of the study