Congestive heart failure is a major health problem and recent estimates indicate that end-stage heart failure with a 2-year mortality rate of 70-80% affects over 60,000 people in the United States each year. For these patients, treatment options are extremely limited. Less than 3,000 heart transplants are available each year because of the severely limited supply of donor hearts. Implantable LVADs, routinely used to support heart transplantation patients who decompensate awaiting a donor heart, were approved by the Food and Drug Administration (FDA) in 2002 for long-term support when heart transplantation is not an option. Few patients, however, achieve sufficient recovery to warrant LVAD explantation and those who do must still contend with ventricular dysfunction. MPCs are normally present in human bone marrow and have been shown to increase the development of blood vessels and new heart muscle cells. The purpose of this study is to determine the safety of injecting MPCs into the heart during LVAD implantation surgery. In addition, this study will examine whether injecting MPCs into the heart is effective at improving heart function.