A new study adds a twist to the ongoing debate over using blood-forming stem cells to repair heart muscle. In the March 21 online issue of Nature, researchers at the Stanford University School of Medicine report that the cells are unable to replace heart muscle after a heart attack, which refutes earlier findings. During the past three years, several groups had reported that stem cells found in bone marrow could lodge in the heart and repair muscle damaged by a heart attack. These stem cells normally reside in the bone marrow, where they constantly replenish red blood cells and immune cells. If the earlier findings were correct and the blood-forming stem cells switched their fates, that could reveal an exciting new path for treating heart attack patients.
