Nearly 1,000 babies are born every year in the U.S. with a heart defect that is difficult to survive.Surgeons treat hypoplastic left heart syndrome with many surgeries, and now doctors want to know if adding stem cells will lead to extended survival.The parents of 4-month-old Josue Salinas Salgado were thrilled their son was finally going home from the hospital.At birth, he was born with a misshapen left ventricle. The right side of his heart struggled to do all the pumping."That right ventricle tires out over time and it becomes dysfunctional. When it becomes dysfunctional, then it can't pump blood efficiently to the rest of the body," said Dr. Sunjay Kaushal, chief of pediatric cardiac surgery at the University of Maryland Medical Center.Doctors treat hypoplastic left heart syndrome with a series of three open-heart surgeries over the course of three years. Josue already had two.The goal is to reconstruct the developing heart so that the right side does the work of both, but the fix doesn't always last.Only about 65 percent of these children have made it to 5 years old."Long-term, they have complications. We're trying to prevent that, we're trying to improve on that outcome," said Kaushal.He led a trial for a new procedure: injecting stem cells into the baby's heart during the second surgery.Josue was one of the first patients to undergo the experimental treatment."We're very grateful, grateful to God for giving us the strength to get through these difficult months and for giving Dr. Kaushal wisdom," said Hidelberto Salinas Ramos, Josue's father.Before he was wheeled into surgery, Josue's parents clasped hands and prayed over their child.His parents hoped the stem cells would give his tiny heart the best chance of beating the odds.The study was a first step to test whether injecting stem cells donated from a stranger into a baby's heart is safe.Josue will still need a third surgery by the time he is 3 years old.