The purpose of the research is to help researchers understand changes in metabolism in patients that develop heart failure.

Inclusion Criteria:

1. Subjects are capable of giving informed consent.

2. Age 19-89

3. Diagnosis of chronic heart failure

4. Any patients scheduled for at least one of the following procedures:

   1. LVAD implantation or as recipient for cardiac transplantation.
   2. LVAD placement both as bridge to transplant and as destination therapy.
   3. LVAD explantation
   4. Valve replacement or repair
   5. Catheterization and myocardial biopsy for idiopathic cardiomyopathy
   6. Coronary artery bypass graft (CABG)

Exclusion Criteria:

1. Life expectancy less than 2 weeks
2. Diagnosed with following co-morbidities: cancer, chronic kidney disease (GFR≤30 or serum creatinine >2.1), active infection or treatment with antibiotics or persistent infectious disease (hepatitis, HIV, etc), cirrhosis, active substance abuse and/or alcohol dependence (≥ 14 alcoholic beverages per week).

Control Myocardial Tissue from Donor Hearts Inclusion Criteria

1. Samples collected from non-failing hearts deemed unsuitable for transplantation by TransLife because of either acute recipient issues or post-harvest evidence of pathology or positive but benign serology.
2. Normal cardiac function from medical records

Exclusion Criteria:

1. Pathological remodeling and extensive infarction with limited non-pathological regions of myocardium.
2. Abnormal or impaired cardiac function from medical records, which are self determinants for rejection as a donor organ.