30-Year Survival After the Fontan Operation in Denmark

This study aimed to evaluate the nationwide 30-year survival among Danish univentricular heart patients who underwent Fontan completion between 1977 and 2023. Secondary objectives included assessment of the impact of era, Fontan type, and ventricular dominance on survival. Finally, clinical performance and the prevalence of select morbidity were described for survivors. The Danish Fontan cohort of 301 patients was identified using surgical registries and digitalized health records. Information on mortality, morbidity, and clinical performance was collected from digital medical records using national personal identification numbers. Survival analysis was conducted using Kaplan-Meier estimates, and morbidity outcomes were compared for three consecutive age groups (< 18 years, 18-29 years, and ≥ 30 years). The 30-year survival rate after Fontan completion was 87%, while freedom from death, transplant, or Fontan takedown was 79%. Improved outcomes were observed for patients undergoing Fontan completion after 1997 and those with a non-hypoplastic left heart syndrome (HLHS) diagnosis. Morbidity, including ventricular dysfunction, arrhythmia, significant atrioventricular valve regurgitation, and protein-losing enteropathy, was present in 38% of survivors and increased with age. The proportion of (self-reported) physically active individuals and their %pred VO2peak declined with age, with those aged ≥ 30 years demonstrating the highest prevalence of Fontan-related complications (56%) and the lowest exercise capacity (51%pred VO2peak). In conclusion, long-term survival after Fontan completion was 87%. Survival has improved in the later era and was superior for those with a non-HLHS diagnosis. The prevalence of select morbidity was substantial at 38% while also displaying an age-related increase.