This study is evaluating an investigational product called CAP-1002 Allogenic Cardiosphere –Derived Cells. Allogenic means tissue or cells that come from another person. CAP-1002 is a product consisting of cells grown from donated heart muscle tissue. The purpose of this study is to look at the safety and feasibility of delivery of allogenic human cardiosphere derived stem cells (CDC's) through the arteries of the heart in participants with heart failure. The study will also determine if CAP-1002 might reduce clinically-meaningful adverse events, meaning some of the symptoms you are experiencing relating to your heart failure may go away and you may feel better. In this study, we will be investigating whether CAP-1002 is safe and begin to look at effectiveness in repairing heart tissue in comparison to placebo (inactive substance) control.