While advanced surgical techniques, ICU care and outpatient management have dramatically improved survival rates for children born with hypoplastic left heart syndrome (HLHS), additional treatment options are still very much needed. That’s why pediatric cardiologists at Children’s of Alabama are eager to join forces with the Mayo Clinic to test stem cell therapy on HLHS patients from Alabama and the surrounding region.
A year after joining the Mayo Clinic’s HLHS Consortium – about a dozen prominent children’s institutions spread across the United States and Canada – Children’s is taking part in clinical research to determine if stem cells from a patient’s own umbilical cord blood can strengthen the right side of the heart.
Born with an array of underdeveloped structures on the left side of their hearts, HLHS patients typically undergo three surgeries over their first four years of life. Children’s treats between 12 and 20 such patients every year.
“This was a uniformly fatal diagnosis before these operations were used,” said Waldemar Carlo, M.D., an associate professor of pediatrics in the Division of Pediatric Cardiology at Children’s and the University of Alabama at Birmingham (UAB). “Outcomes are ever-improving for this diagnosis, and we’ve gotten the first-year mortality down to under 10%. But we know that the decreasing function of the right ventricle over time limits how long these patients can live.”
The Phase 2 clinical trial, in which Children’s is completing enrollment, is based on successful Phase 1 results and will further determine the safety and efficacy using cell-based regenerative therapy to help manage HLHS. Parents expecting babies known to have HLHS are approached before childbirth and offered the opportunity to bank their baby’s umbilical cord blood. Stem cells derived from that blood are then injected directly into the infant’s right ventricular muscle during second-stage (Glenn) surgery.
To compare outcomes over time, the trial will also include a placebo arm of patients who do not receive stem cells during second-stage surgery. Several HLHS patients at Children’s will be included in each arm.
“The thought with this therapy is that stem cells would initiate a response in the right ventricle to strengthen the heart muscle over time – hopefully preserving its function longer than would otherwise happen,” Carlo said.
“We were chosen because we have very good clinical results in the care of children with HLHS at Children’s of Alabama,” Carlo added. “That is a prerequisite before participating in clinical research using novel therapies. It’s certainly an honor to participate with these other excellent centers.”
