P2.018: Fontan Long-term Outcomes: Lessons from Two Decades of Single-Institution Experience

Background: The Fontan procedure represents the final stage of surgical palliation for patients born with single ventricle heart disease. Despite ongoing advances in surgical techniques, long term outcomes and survival remain highly variable. This study aims to evaluate outcomes and share insights from over two decades of institutional experience.

Methods: A retrospective analysis included all Fontan patients who are following up at our institution up to Feb 2024. The analysis included 350 Patients, 297 who underwent an extracardiac approach and 53 patients who had a lateral tunnel approach. Major Fontan-related complications included protein losing enteropathy (PLE), cirrhosis, severe systolic dysfunction, Fontan failure, transplant, and death. Fontan failure was defined as meeting at least one of the following criteria: NYHA class IV, referral for transplant evaluation, or persistent PLE/plastic bronchitis without remission for ≥6 months. The onset was determined based on the date of the first recorded event. Kaplan-Meier analysis was used to assess survival, stratified dominant ventricle and fenestration. Univariable logistic regression was performed to explore associations between patient characteristics and specific complications.

Results: Out of 350 patients, 57% were male. The cohort included 225 with LV dominance and 125 with RV dominance. Survival was significantly worse in RV-dominant patients compared to those with LV dominance (p = 0.0052; HR [Hazard ratio] = 2.17 [inverse of 0.46]), with a median event-free survival of 19.3 years in the RV group. In the univariable logistic regression, RV dominance was a strong predictor of adverse outcomes, including Fontan failure (OR [Odds ratio] = 3.44, p = 0.016) and transplant (OR = 3.51, p < 0.001). Older age at Fontan completion was associated with increased risk of cirrhosis (OR = 1.12 per year, p < 0.01). Sex and race were not significantly associated with survival or major complications.

Conclusion: Right ventricular dominance and older age at Fontan completion were key predictors of adverse outcomes, including Fontan failure and transplant. In contrast, sex, race, and fenestration were not significant. These findings highlight the importance of ventricular morphology in long-term prognosis. Future studies should focus on incorporating these predictors into personalized risk models to improve post-Fontan care and outcomes.