It is estimated that approximately 5 million people in the United States have heart failure, with more than 500,000 new cases diagnosed each year. Heart failure is a disorder that develops over many years and can be attributed to a number of conditions, including heart attack, coronary artery disease, diabetes, high blood pressure, or congenital heart defects. Although there are many treatment options for heart failure, people with end-stage heart failure may benefit most from a heart transplant. However, the number of donor organs available remains limited, making alternative treatments for people with end-stage heart failure imperative. LVAD support, which has traditionally been used as a bridge to transplant, may also provide an alternative life-saving measure for patients with advanced end-stage heart failure. The mechanical circulatory support provided by LVAD may allow the left side of the heart to rest and recover enough so that removal of the device is possible and a heart transplant is no longer needed, at least temporarily. However, more research in this area is needed. Using data collected from patients who have undergone LVAD implantation, this study will attempt to better assess heart recovery and to generate criteria for identifying patients eligible for the removal of LVAD support.