Optimizer System With ODOCOR II CCM™ Leads

Inclusion Criteria:

1. Patient signed and dated informed consent form
2. Male or non-pregnant female, aged 18 or older
3. Left ventricular ejection fraction of 25-45% (inclusive)
4. Diagnosed with NYHA Class III or IV heart failure
5. Stated willingness to comply with all study procedures and availability for theduration of the study
6. Medically stable and with no significant mental illness in the judgement of theprincipal investigator

Exclusion Criteria: 1. Infiltrative or inflammatory cardiomyopathy (e.g. amyloid, hemochromatosis,myocarditis, hypertrophic cardiomyopathy, Fabry's disease, cardiac tumor) 2. Primary heart failure due to uncorrected mitral valve disease, or mitral valve repairor clip within 3 months of the baseline testing visit. 3. IV inotropes, hemofiltration, or any form of positive inotropic support within 30 daysbefore the baseline testing visit, including continuous IV inotrope therapy 4. Myocardial infarction within 3 months of the baseline testing visit. 5. Undergone a CABG procedure within 3 months90 days or a PTCA procedure within 30 daysof the baseline testing visit. 6. Undergone a cardiac ablation procedure within 90 days prior to consent. 7. Prior heart transplant or ventricular assist device 8. Mechanical tricuspid valve 9. Receiving cardiac resynchronization therapy (CRT) or indicated for Class I CRTimplantation according to the ACCF/AHA/HRS guidelines for device-based therapy 10. Currently on dialysis 11. Currently undergoing active chemotherapeutic and/or radiation treatment for cancer 12. Participating in another cardiac investigational device study at the same time 13. Patient is in a vulnerable population (such as significant mental disability,prisoner) that in the judgement of the PI impedes ability to provide informed content. 14. Expected lifespan of less than 12 months from time the baseline testing visit. 15. Resting heart rate >110 bpm at the time of the baseline testing visit 16. Current drug or alcohol use or dependence that, in the opinion of the siteinvestigator, would interfere with adherence to study requirements 17. Subjects currently admitted to the hospital with a primary diagnosis of heart failure