Coronary artery disease (CAD) remains the leading cause of morbidity and mortality worldwide and is predicted to be the leading cause of death by 2020. In the US, it is estimated that cardiovascular disease affects 60 million patients costing the healthcare system approximately $186 billion annually. Approximately two-thirds of patients sustaining a myocardial infarction do not make a complete recovery and often are left with debilitating congestive heart failure. Despite the advances in medical treatment and interventional procedures to reduce mortality in patients with CAD, the number of patients with refractory myocardial ischemia and congestive heart failure is rapidly increasing. For end-stage heart failure, heart transplantation is the only successful treatment. However, the ability to provide this treatment is limited by the availability of donor hearts. Therefore, alternative therapies in the prevention and treatment of end-stage heart failure are needed.
Critical to any heart repair strategy is the need to provide vessels to allow for an adequate blood supply to nourish the heart. Our results demonstrate that human embryonic stem cell (hESC)-derived hemangioblasts can create new blood vessels and improve blood flow in a rodent model of myocardial infarction. Subsequent studies with hESC-derived endothelial progenitor cells decreased MI size and improved LV function in a mouse model of myocardial ischemia. Studies are in progress to improve the efficiency and effectiveness of hESC-derived endothelial progenitor cells to create new blood vessels.
Strategies to improve efficiency and effectiveness of stem cell therapy include the use of extracellular matrix proteins (components that make up the structural aspect of the heart) to increase the survival of the cells or the use of antibodies to direct and link the cells to the damaged heart muscle. We have demonstrated that antibodies can direct stem cells to injured myocardial tissue. Continued studies are in progress to perform studies needed for the submission of an IND. The development of peptide-modified scaffolds for the treatment of chronic heart failure has produced initial proof of concept studies that a tissue engineering approach for restoration of an injured heart is possible. Additionally, we have demonstrated that extracellular matrix derived peptides can recruit endogenous cardiac stem cells. Further development of a biopolymer scaffold for the treatment of chronic heart failure is in progress.