Characteristics Associated with Poor Long-Term Outcomes in Patients with Fontan Palliation: A Case-Control Study

The Fontan procedure provides long-term palliation for patients with single-ventricle physiology, but long-term outcomes remain limited by progressive Fontan circulatory failure. Early identification of patients at risk for adverse outcomes is critical to guide surveillance and management strategies. We aimed to identify peri-Fontan factors associated with mortality or need for advanced cardiac therapies in Fontan patients. We conducted a retrospective matched case-control study of patients who underwent Fontan completion between 2000 and 2023 at a single tertiary congenital heart center. Cases were defined as patients who experienced death, ventricular assist device (VAD) implantation, or heart transplantation after Fontan completion. Each case was matched with three controls by year of Fontan surgery and duration of follow-up. Pre-Fontan hemodynamics, cardiac anatomy, and perioperative variables were analyzed using conditional logistic regression. A total of 53 cases who experienced death, VAD implantation, or heart transplantation were matched to 151 controls. The median age at Fontan failure was 11.5 years (IQR 6.9-16.1), occurring a median of 8.6 years (IQR 3.8-13.8) after Fontan completion. In multivariable analysis, the factors independently associated with death/transplant/VAD implantation were systemic right ventricular morphology (adjusted odds ratio [aOR] 6.87, 95% CI 2.07-22.8, p = 0.002), pre-Fontan Glenn/hemi-Fontan pressure > 12 mmHg (aOR 4.72, 95% CI 1.74-12.8, p = 0.002), and postoperative hospital length of stay > 12 days (aOR 8.57, 95% CI 2.78-26.4; p = 0.0002). Systemic right ventricular morphology, elevated pre-Fontan Glenn/hemi-Fontan pressure, and prolonged postoperative hospitalization are independently associated with long-term mortality or need for advanced cardiac therapies after Fontan completion. These findings add to the growing body of literature identifying peri-Fontan factors associated with adverse long-term outcomes and support the importance of perioperative hemodynamics and postoperative recovery in long-term Fontan risk assessment.