Stem Cells Heal Hearts

BACKGROUND: According to the National Institutes of Health, coronary heart disease is the number one cause of death for men and women in the United States. It's caused by a narrowing of the coronary arteries that supply blood to the heart and often results in a heart attack. About 1.1 million people have a heart attack every year in the United States. Nearly half of those are fatal -- with death occurring within one hour of the start of symptoms before the person ever reaches the hospital. Pre-existing heart diseases can increase the risk of having a heart attack. Your age also ups the ante. Heart attack risk increases in men after age 45 and after age 55 in women. The risk factors for a heart attack that are within your control include smoking, high blood pressure, high cholesterol, being overweight, a sedentary lifestyle and diabetes that is not well-controlled.

FIXING THE DAMAGE: Currently, there is no way to fix the heart muscle once it's been damaged by a heart attack. Gary Schaer, M.D., from Rush University Medical Center in Chicago, says, "What happens in a heart attack is that part of the heart muscle dies and essentially becomes a scar and none of the muscles supplied by that artery function anymore." The earlier a heart attack is treated, the less damage will result. But time is of the essence. Many times, patients do not present to the hospital right away. The longer they wait, the more damage is being done to their heart muscle. Dr. Schaer says, "Once it is dead, it does not come back. The heart muscle doesn't have any great ability to repair itself once it has been damaged." But new science may soon change that…

RE-GROWING HEARTS: Researchers at about 16 sites across the United States are involved in a study on adult donor stem cells to repair the heart muscle after a heart attack. Stem cells are premature cells that can grow and develop into a variety of different tissues. In the study, patients are infused (through a simple IV line) with either adult donor stem cells or a placebo. They are infused between three and nine days after they have a heart attack. Dr. Schaer says, "The theory behind using stem cells to help patients that have had a recent heart attack is very simply to try to repair the part of the heart muscle that has been damaged by that loss of blood supply." When the stem cells are infused, they hone in on the damaged area of the heart muscle and go to work repairing it.

A PROMISING FUTURE: Earlier studies have shown promise for stem cells to treat heart failure by improving the heart's pumping ability. Those studies have used the patient's own stem cells, which were extracted from their hip bones. Dr. Schaer says the use for donor stem cells to treat heart attacks is the next frontier. The benefits of using donor cells are many. One, they are ready right away, and there is no need to perform any procedure on the patient to extract his/her own stem cells. Two, a single donor could supply enough stem cells to help an endless number of people. The donor's cells are taken and multiplied in a lab where they are then frozen for future use. Three, the donor stem cells come from a young, healthy adult. Dr. Schaer says, "These healthy young stem cells may be more efficacious. They may be more able to … help restore the heart muscle pumping function [than the patient's own stem cells]." Dr. Schaer says there is no risk of rejection with donor stem cells as the cells are too premature to trigger rejection. He says, "The promise of stem cells is the promise that these cells could be given to grow new parts of the body that have been damaged." At this time, results of the study are not known as the study is still ongoing. Recruitment for the study is nearly complete.