Those subjects who fulfill all inclusion and exclusion criteria based upon baseline test results will be randomly assigned in a 1:1 ratio to either the OPTIMIZER System plus optimal medical therapy (OMT) or to a control group receiving OMT alone. All randomized subjects will be followed for 24 weeks and shall receive the same study related assessments throughout the course of the study. In addition, all subjects will continue to receive OMT for the treatment of their heart failure. Mortality will be reported out to 2 years.