CHLA Takes On Trial of Potential Stem Cell Procedure in Treating HLHS

Children’s Hospital Los Angeles (CHLA) has announced that it will be participating in a new clinical trial with the hopes of improving quality of life (QOL) outcomes for children with hypoplastic left heart syndrome (HLHS), a congenital heart defect in which the left ventricle is severely underdeveloped.

"We're proud to be part of this select group of institutions," says Vaughn Starnes, MD, co-director of the Heart Institute at CHLA and chair, Department of Surgery, at the Keck School of Medicine of the University of Southern California, in a press release. "As a leading center for medical and surgical treatments for HLHS, we want to be at the forefront of the next transformative therapy for treating this complex condition."

The HLHS Consortium was launched by the Mayo Clinic in Minnesota in 2017 and includes three regional centers: CHLA, Children's Hospital of Philadelphia, and Minnesota Children's Hospital.

HLHS causes oxygen-rich blood to bypass the underdeveloped left side of the heart. There may not be symptoms until a few days after birth, as blood continues to flow through openings on the left and right side that pump blood to the lungs and body.

When these openings close, oxygen-rich blood cannot reach the body. Symptoms will begin to surface, including problems breathing, pounding heart, weak pulse, and bluish skin color.

If not effectively treated, HLHS is fatal and infants will die in the first few days of life.

Patients undergo a series of 3 surgeries during the first 3 years of life to ensure the right side of the heart is the main pumping chamber of the muscle to improve blood flow. However, doctors have found that these surgeries do not have a lasting effect, resulting in heart failure and the need for a transplant.

The new clinical trial had the Mayo Clinic collecting the umbilical cord blood of infants with HLHS, where they had surgery within the first few days of life at CHLA. Six months later, the second heart surgery takes place where stem cells from the umbilical cord are injected into the heart. Researchers believe that this will stimulate muscle growth in the heart.

The third surgery, which takes place at 3 years of age, is called the Fontan procedure.

This first-of-its-kind clinical trial combines pioneering surgical techniques with regenerative medicine. "This is one of the earliest efforts at harnessing the power of stem cell technology for the care of children with a serious cardiac disease," says Ram Kumar Subramanyan, MD, PhD, a cardiothoracic surgeon who is heading the HLHS study in CHLA's Heart Institute, said in a press release.

The consortium hopes to recruit 20 children for the Phase 1 umbilical cord blood study.