Heart disease leading to cardiovascular failure is a major public health issue in the United States with a considerable burden for the health care system. Despite recent progress to advance stem cell-based therapy for patients, heart failure carries a five-year mortality that rivals most cancers. This proposal describes an approach to control and pattern three distinct stem cell populations derived from the human heart to promote superior repair and regeneration after myocardial infarction. Regenerative capacity of the heart is mediated through multiple distinct populations of stem cell types that are the subject of ongoing intense study. In the past decade, isolation and characterization of c-kit+ cardiac progenitor cells (CPCs), mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) have provided substantial insight to the capabilities of stem cells to rebuild the damaged heart and advance clinical therapy. Clinical trials have proven the efficacy and safety of autologous and allogeneic cell delivery to human patients, yet improvements in cardiac function and reduction in scar tissue remain modest and far below that needed for restoration of normal functional output. The work presented in this dissertation project overcomes these current cell-based limitations by using a novel method for improving myocardial repair: CardioClusters, a three-dimensional microenvironment consisting of CPCs, MSCs and EPCs. The innovation of this project is the creation of CardioClusters with the ability to capitalize upon beneficial attributes of multiple human stem cells from a single human heart providing a clinically relevant translational strategy. Collectively, studies in this dissertation will pave the way for interventional approaches to selectively adapt stem cell behavior and merge beneficial attributes of stem cell populations found within the human heart for prevention of heart failure after cardiomyopathic injury.