The invention provides compositions comprising modified stem cells containing a transgene that affects the expression of at least one gene that inhibits or promotes cardiomyogenesis. In particular, the invention discloses compositions comprising cardiac stem cells, wherein said cardiac stem cells comprise a transgene encoding a microRNA. The compositions of the invention find use in the treatment of cardiovascular disorders, such as myocardial infarction. Methods of repairing damaged myocardium in a subject using the modified stem cells are also disclosed.
