Clinical Trial: Long-term Outcomes of Children With Hypoplastic Left Heart Syndrome and the Impact of Norwood Shunt Type

Study Status: Enrolling by invitation
Recruit Status: Enrolling by invitation
Study Type: Observational

Official Title: Long-term Outcomes of Children With HLHS (Hypoplastic Left Heart Syndrome) and the Impact of Norwood Shunt Type (A Study Conducted by the Pediatric Heart Network)

Brief Summary: The purpose of this study is to compare direct and indirect measures of right ventricular (RV) systolic and diastolic function between 11 year old subjects who had been randomly assigned to receive a right ventricle to pulmonary artery shunt (RVPAS) vs. a modified Blalock-Taussig shunt (MBTS) at the time of the Norwood operation.

Detailed Summary:

The Single Ventricle Reconstruction (SVR) trial was the first multicenter, randomized clinical trial to compare two operations in the field of congenital heart disease.8,11 Children with HLHS and other related single RV lesions were enrolled and randomized to receive either a MBTS or a RVPAS at the time of the initial Norwood procedure. This landmark study provided extraordinary insight not only into the consequences of both shunt types, but also into the course, treatment responses and short- and mid-term outcomes for these medically complex patients. Through the SVR Trial and SVR Extension Study (SVR II), outcomes, including but not limited to the primary outcome of transplant-free survival, have now been evaluated in this patient cohort when the last enrolled patient reached 12 months and again at 3 years of age. While early post-operative transplant-free survival during the interstage period7 and at one year8 was better for those children randomized to a RVPAS, survival by the 3-year evaluation appeared equivalent between the two shunt types. Moreover, RVEF was somewhat diminished and the number of interventions was higher in the RVPAS group.12 These findings raised concern that the RV dysfunction in the RVPAS group may be progressive, leading to significantly worse long-term outcomes; if so, the benefits of the RVPAS for short-term survival may be outweighed by longer-term morbidity and mortality. Thus, the optimal surgical approach for newborns with HLHS and related single RV lesions remains unclear.

The Pediatric Heart Network (PHN) Investigators have a unique opportunity and responsibility to analyze the effect of the type of systemic-to-pulmonary artery shunt placed during the Norwood procedure on longer-term survival, as well as to define its effect on other long-term outcomes in this multi-institutional cohort of exquisitely characterized subjects with single R
Sponsor: New England Research Institutes

Current Primary Outcome: RV ejection fraction (RVEF) at 11 years, as measured by cardiac magnetic resonance (CMR). [ Time Frame: 10 to 12 years of age for each participant (11 years ± 1 year) ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

  • The incidence of death or cardiac transplantation between those randomized to receive a RVPAS vs. a MBTS at the time of the Norwood operation. [ Time Frame: 11 years ± 1 year to 16 years ]
  • The exercise tolerance between those randomized to a RVPAS vs. a MBTS. [ Time Frame: 11 years ± 1 year to 16 years ]
  • The incidence of arrhythmias between those randomized to a RVPAS vs. a MBTS. [ Time Frame: 11 years ± 1 year to 16 years ]
  • The neurodevelopmental outcomes at 11 years of age in those randomized to a RVPAS vs. a MBTS [ Time Frame: 11 years ± 1 year ]
  • Develop risk stratification models for 1) cardiac outcomes, 2) transplant-free survival, and 3) neurodevelopmental outcomes. [ Time Frame: 11 years ± 1 year to 16 years ]
  • Collect specimens from subjects and their parents to further develop the biologic specimen repository. [ Time Frame: 11 years ± 1 year to 16 years ]


Original Secondary Outcome:

  • To compare the incidence of death or cardiac transplantation between those randomized to receive a RVPAS vs. a MBTS at the time of the Norwood operation. [ Time Frame: 11 years ± 1 year to 16 years ]
  • To compare exercise tolerance between those randomized to a RVPAS vs. a MBTS. [ Time Frame: 11 years ± 1 year to 16 years ]
  • To compare the incidence of arrhythmias between those randomized to a RVPAS vs. a MBTS. [ Time Frame: 11 years ± 1 year to 16 years ]
  • To compare neurodevelopmental outcomes at 11 years of age in those randomized to a RVPAS vs. a MBTS [ Time Frame: 11 years ± 1 year ]
  • To develop risk stratification models for 1) cardiac outcomes, 2) transplant-free survival, and 3) neurodevelopmental outcomes. [ Time Frame: 11 years ± 1 year to 16 years ]
  • To collect specimens from subjects and their parents to further develop the biologic specimen repository. [ Time Frame: 11 years ± 1 year to 16 years ]


Information By: New England Research Institutes

Dates:
Date Received: May 22, 2015
Date Started: June 2015
Date Completion: June 2025
Last Updated: September 27, 2016
Last Verified: September 2016