The problem: Until recently, when a patient suffering a heart attack arrived at a hospital, doctors could open the blocked blood vessel and restore blood flow to prevent further damage. But there was nothing they could do to reverse the harm already done. That damage — scarring that can kill up to 50 percent of the heart — leaves patients with difficulty breathing, loss of energy and the inability to do things such as walk up stairs. Some patients need transplants. And some end up with hearts so weak they die.

The solution: Now doctors can repair that damage. In U.S. Food and Drug Administration-approved trials, a number of hospitals across the country have been injecting the patient’s stem cells into the heart and watching as the damaged muscle is restored to its previously healthy state. The weakened heart becomes pliable again. It contracts normally. And it pumps blood closer to the way it did before the heart attack. That research also found that the earlier the stem cells are injected, the better the heart repairs itself.

But there’s a downside to the treatment.  Read More