Long-term survival in patients with univentricular heart: A nationwide, register-based cohort study.

Background: Children with univentricular heart (UVH) have a limited life expectancy without early treatment. Long-term survival in UVH, in an unselected nationwide cohort, is unclear. Objectives: To determine long-term survival in patients with UVH including non-operated patients compared with a control population in Sweden. Methods: Patients with UVH born between 1970 and 2017 were identified from the National Registers and were matched for birth year and sex with 10 individuals without congenital heart disease. Follow-up was from birth until death, transplantation, or the end of study. Mortality risk was estimated by Cox proportional regression models and Kaplan-Meier survival analysis. Results: We included 5075 patients with UVH including 758 (14.9%) patients with hypoplastic left heart syndrome (HLHS), and 50,620 matched controls. Median follow-up time was 13.6 (IQR 0.7; 26.8) years. The hazard ratio for death in patients with UVH was 53.0 (95% confidence interval, 48.0-58.6), and for HLHS, 163.5 (95% CI, 124.3-215.2). In patients with HLHS, 84% of those who were born between 1982 and 1993 died or had transplantation during the first year of life compared with 29% born between 2006 and 2017. In patients with UVH without HLHS, death/transplantation in the first year of life declined from 36% in those born between 1970 and 1981 to 8.7% in those born between 2006 and 2017. Conclusions: The risk of mortality was >50 times higher in patients with UVH than in controls. The survival rate increased with a later decade of birth but was still <75% in patients born with HLHS.