Hypoplastic left heart syndrome (HLHS) is a type of congenital heart disease which affects 1 in every
1,000 children. Treatment for this condition consists of three rounds of surgery. However, clinical trials in regenerative medicine are being explored for alternative forms of treatment that are less invasive. The answer may lie in cord blood stem cells. A study conducted by Mayo Clinic just released the findings of their 2015 phase one clinical trial study which show promising results. What does this study suggest? Read on to learn more.
What is HLHS?
Hypoplastic left heart syndrome is a heart condition in which the left side of the heart is underdeveloped, or, in some cases, non-existent. This places extra stress on the right side of the heart, which leads to the eventual decline of the single right ventricle. There is a high mortality rate of patients with HLHS that do not undergo palliative surgery. Surgery takes place in three rounds: one at birth, one around 3-6 months, and one near 18 to 30 months of age. Even with treatment, complications can occur throughout the lifetime of a patient. The cause of the disease is not known and can occur in otherwise healthy babies.
Alternative Treatments of HLHS
While heart surgery and heart transplants may be used as a retroactive means of providing a short-term, unpredictable solution to the problem, stem cell therapy is being explored to provide a more stable, preventative means of healing through regeneration. On our page pertaining to heart diseases, we discuss the fact that stem cells can be used to help replace damaged heart tissue and valves and establish new vessels to supply them with blood. Stem cells can also be used to build entirely new heart tissue.
Due to the preliminary research and positive outcomes of “first-generation” stem cell therapy observed in animal models, the FDA approved stem cell therapy for heart-related conditions in people. One source states stem cell-based therapeutics have shown promise in adult patients with ischemic and nonischemic dilated cardiomyopathy. The source also suggests that because of the given limitations of standard therapies for HLHS, it has become the most common form of congenital heart disease to be treated with investigational stem cell therapies.
Moreover, an article published in the American Heart Association Journals revealed that the therapeutic use of stem cells has the potential to reverse myocardial injury and improve cardiac functions. It also goes on to state that over the past two decades, over 200 clinical trials have taken place to test the safety and feasibility of stem cells in various cardiovascular diseases and has revealed that most cell types are safe and effective.
Potential of Cord Blood Stem Cells
In 2015, the Mayo Clinic conducted a phase 1 clinical study involving ten babies diagnosed with hypoplastic left heart syndrome before birth. The initial round of the study focused on the safety and feasibility of stem cells to strengthen the heart muscle of children with HLHS. During this trial, infants were infused with 35 milliliters of cord blood which was collected at the time of their birth. Their laboratory manufactured a stem cell concoction of highly specialized umbilical cord stem cells which was injected into the heart muscle at the time of the baby’s second surgery.
Each of the 10 patients underwent the second surgery, and there were no reports of safety concerns after six months of follow-up data. Following the heels of the success of this trial, the HLHS Consortium is conducting a phase II study with 50 infants. The objective of this study will be centered on the extent to which umbilical stem cells improve heart function in these children.
As clinical trials progress past the “first-generation” stage, and more findings indicate success in terms of treatment, umbilical cord blood stem cells may be deemed the most valuable and flexible source of cells in regenerative medicine. As we continue to do our part to move regenerative treatments forward, we look forward to updating you on the exciting advancements taking place using cord blood.
For a recap of Mayo Clinic’s research on HLHS patients, please see the following video: