Stem cell therapy for failing hearts: there is something else beyond the cells

Heart failure (HF) affects a rapidly growing popula-tion of patients. Despite improvements in the understand-ing and therapy of many stages of cardiovascular disease, there has been little progress in treating HF. In late-stage disease, current options are cardiac transplantation and mechanical support-options that are limited to a small pa-tient collective. The ischemically injured failing heart lacks contractile myocardium, functional vasculature, and electri-cal integrity, which has made treatment of the underlying injury untenable in the past. Restoring all of these compo-nents at once seems to be an overwhelming challenge.