Eligibility Criteria:
Inclusion Criteria:
* Chronic ischemic or non-ischemic cardiomyopathy. Subjects with ischemic cardiomyopathy must have at least one major coronary vessel with Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow.
* Left ventricular ejection fraction (LVEF) ≤35%
* Diagnosis of New York Heart Association (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 (alanine aminotransferase \[ALT\], aspartate aminotransferase \[AST\], 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