Outcomes of Hypoplastic Left Heart Syndrome with and without Restrictive Atrial Septum

Abstract – Outcomes of Hypoplastic Left Heart Syndrome with and without Restrictive Atrial Septum Jake Weston, OMS-II, Bryan Noblett, OMS-II, James Kuo, MD Introduction: Hypoplastic Left Heart Syndrome (HLHS) is a congenital heart defect characterized by inadequate development of a functional left ventricle to the point where it is unable to support systemic circulation. Patients often undergo a series of palliative surgeries beginning with the Norwood procedure within several weeks of life, which has greatly improved the mortality rate associated with this condition. However, about 6-22% of these patients also have an intact atrial septum (IAS) or restrictive atrial septum (RAS), which is associated with significantly worse survival rates. Multiple strategies have been developed in order to treat this complication. The Cook Children’s Heart Center tends to perform early Norwood procedures (day 0-1 of life), and one of the goals of this study is to analyze the outcomes of performing early Norwood procedures. It was hypothesized that the Cook Children’s institutional approach of early Norwood procedure for patients with HLHS with RAS is at least comparable, if not superior, to other approaches in terms of survival and long term outcomes. Methods: This was a retrospective study of patients who had a Norwood procedure done at Cook Children’s Hospital from 2014 – 2016; 36 patients met inclusion criteria. Data were collected for variables of significance, including presence of restrictive atrial septal defect (ASD), pre- vs. post-natal diagnosis of HLHS, survival to discharge, and mortality. Using logistic regressions, we examined the effect of ASD and pre- vs. post-natal diagnosis on survival at discharge, and overall mortality. Results: Thirty-one of 36 (86%) patients survived. Those with ASD (4/6) were not statistically significantly less likely to survive than those without ASD (27/30), p=.13, and those born pre-natally (23/26) were not significantly less likely to survive than those born post-natally (8/10), p=.51. Discussion: The survival rates at discharge were slightly higher than published survival rates for patients with and without restrictive ASD. While the results are preliminary, and further research with a larger sample size is needed, we believe our current data shows a trend that supports our hypothesis.