Children's Hospital of Philadelphia Researchers Spotlight Adults with Hypoplastic Left Heart Syndrome (HLHS) Thriving Without Transplants

Study Highlights Largest Single-Center Cohort of Adults with HLHS with Longest Follow-up

PHILADELPHIA, June 17, 2025 /PRNewswire/ -- Researchers at Children's Hospital of Philadelphia (CHOP) reported long-term clinical outcomes for the largest single center cohort of individuals who underwent complex reconstructive surgery for hypoplastic left heart syndrome as newborns. In this cohort, more than 30% survived without a transplant to at least 35 years of age. Among these individuals, there was a significant group of adults who reported good to excellent clinical outcomes and quality-of-life (QOL), consistent with a "high-performing" Fontan phenotype. The findings were published today in the Journal of the American College of Cardiology. 

Prior to this study, limited data existed concerning longer-term outcomes for patients with HLHS. To bridge this gap, researchers examined long-term survival and the impact of patient factors on survival for newborns with HLHS, as well as functional and health outcomes, including QOL in adulthood.

"Our study highlights the impact of CHOP's pioneering surgical approaches to pediatric heart disease," said J. William Gaynor, MD, a lead study author and surgeon in the Cardiac Center at Children's Hospital of Philadelphia. "While more research is needed, our findings offer hope for a future where high-functioning adult patients with CHD are the norm."

In this retrospective study, researchers analyzed patients with HLHS and associated variants who underwent complex open-heart surgeries between January 1984 and December 2023. The authors noted that while survival has plateaued over the past two decades, they are encouraged by the adult individuals reporting good to excellent health and few Fontan-related complications without a transplant.

The study findings also underscore the importance of maintaining cardiac care for adults with congenital heart disease. CHOP's Philadelphia Adult Congenital Heart Disease Center and Fontan Rehabilitation, Wellness, Activity and Resilience Development program (FORWARD) are designed to provide specialized care, evaluation and ongoing monitoring of individuals with single ventricle heart defects and Fontan circulation. In the past, research has primarily focused on identifying "risk factors" associated with worse survival and outcomes for patients with HLHS. However, in the future, CHOP's innovative programs addressing adults with CHD will be instrumental in helping researchers better understand what is driving patient success.

"Moving forward, based on these study findings, we plan to focus more research on adults with CHD, looking at why they are doing well without a transplant," said Jack Rychik, MD, Director of the FORWARD program at Children's Hospital of Philadelphia. "For us, success is seeing our patients thrive as adults. We are committed to finding new, personalized ways to help them heal, grow stronger and live their best lives."

Dr. Gaynor said they will continue to follow the cohort of adult individuals to better understand their lives in greater depth, including health and wellness, approach to exercise, emotional and cognitive abilities, as well as careers and relationships.

This study was funded by a grant from Big Hearts to Little Hearts, an organization aimed at improving the lives of children and adults with CHD through research, programs, and advocacy. Additional funding includes the Mortimer J. Buckley Jr. M.D. Endowed Chair in Cardiac Surgery, the Thomas L. Spray, MD Endowed Chair in Pediatric Cardiothoracic Surgery and the Daniel M. Tabas Endowed Chair in Pediatric Cardiothoracic Surgery at CHOP.

Gaynor et al. "Long-term Survival and Patient Reported Outcomes after Staged Reconstructive Surgery for Hypoplastic Left Heart Syndrome." JACC. Online June 16, 2025. DOI: 10.1016/j.jacc.2025.04.028.

About Children's Hospital of Philadelphia:
A non-profit, charitable organization, Children's Hospital of Philadelphia was founded in 1855 as the nation's first pediatric hospital. Through its long-standing commitment to providing exceptional patient care, training new generations of pediatric healthcare professionals, and pioneering major research initiatives, the hospital has fostered many discoveries that have benefited children worldwide. Its pediatric research program is among the largest in the country. The institution has a well-established history of providing advanced pediatric care close to home through its CHOP Care Network, which includes more than 50 primary care practices, specialty care and surgical centers, urgent care centers, and community hospital alliances throughout Pennsylvania and New Jersey. CHOP also operates the Middleman Family Pavilion and its dedicated pediatric emergency department in King of Prussia, the Behavioral Health and Crisis Center (including a 24/7 Crisis Response Center) and the Center for Advanced Behavioral Healthcare, a mental health outpatient facility. Its unique family-centered care and public service programs have brought Children's Hospital of Philadelphia recognition as a leading advocate for children and adolescents. For more information, visit https://www.chop.edu. 

Contact: Natalie Solimeo
Children's Hospital of Philadelphia
267-426-6246
[email protected]

SOURCE Children's Hospital of Philadelphia