Compositions for delaying, attenuating or preventing cardiac remodeling following cardiac injury contain fibroblast cells in a dosage providing an effective amount to delay, attenuate or prevent cardiac remodeling following cardiac injury. These cells are obtained by biopsy, preferably from the patient, then cultured and proliferated prior to use. It has been discovered that certain subpopulations of these cells are even better suited for repair or regeneration of tissue, the cells exhibiting properties similar to stem cells or multipotent cells. In a preferred embodiment, the cells are administered to delay, attenuate or prevent cardiac remodeling following cardiac injury.