Fontan Outcomes Network: Baseline Findings From 1121 Participants

25 Mar 20264 min read0 viewsJournal Feed

GIST

Circulation, Ahead of Print. BACKGROUND:Survival after Fontan palliation for single ventricle heart disease has improved substantially, yet the long-term trajectory remains poorly defined.

The Fontan Outcomes Network, a learning health network of 38 congenital heart centers in the United States and Canada, was established to address this gap. We report baseline characteristics and early findings from the first 1121 participants enrolled in this prospective clinical registry.METHODS:We performed a cross-sectional analysis of individuals who had undergone Fontan palliation enrolled in the Fontan Outcomes Network from August 2022 through August 2024.

Demographic, clinical, imaging, procedural, and medication data were analyzed descriptively, overall and by age group (<12, 12 to <18, and ≥18 years).RESULTS:A total of 1121 participants were enrolled (mean age, 16.3±10.2 years; 471 [42%] female). Hypoplastic left heart syndrome (n=431 [38.5%]) and right ventricular–dominant anatomy (n=615 [54.9%]) were the most common primary cardiac diagnoses, especially in younger age groups.

Extracardiac conduit was the most frequent Fontan type (n=749 [66.8%]).

Clinical Editorial

Summary

A regional, multi-center registry framework for Fontan patients: study design and early demographics

Context and purpose

The Fontan Outcomes Network (FON) is a collaborative learning health network spanning 38 congenital heart centers in the United States and Canada.
The project aims to illuminate long-term trajectories after Fontan palliation for single-ventricle heart disease by capturing prospective data across a broad, multicenter cohort.

Cohort and design characteristics

Study type: cross-sectional analysis of individuals who underwent Fontan palliation.
Enrollment window: August 2022 to August 2024.
Population size and participation: 1121 participants enrolled, forming one of the largest prospective, multicenter Fontan data sets reported to date.
Baseline scope: comprehensive collection of demographic, clinical, imaging, procedural, and medication information.
Age stratification: analyses conducted overall and by three age groups—less than 12 years, 12 to less than 18 years, and 18 years or older.

Etiology, anatomy, and Fontan type

Most common primary diagnoses: hypoplastic left heart syndrome (about 38.5%) and right ventricular–dominant anatomy (roughly 54.9%), with distribution skewed toward younger individuals.
Fontan configuration: extracardiac conduit emerged as the predominant Fontan type (approximately 66.8%).

Arrhythmia, thrombosis, and Fontan-related morbidity

Fontan-related adverse events: documented in about 59% of participants, indicating substantial disease burden within this cohort.
Specific events: chylous pleural effusions occurred in roughly 9.6%, Fontan-associated thrombosis in 7.1%, and nonperioperative stroke in 6.5%.
Arrhythmia history: present in 41.3% of patients overall, with prevalence increasing with age.
Acquired comorbidities: identified in 57.5% of participants, including asthma (12%) and sleep apnea (9%), with higher burden in older age groups.

Medication patterns and clinical focus

Antidepressants were prescribed in 11.8% overall, with adult prevalence at 23.6%.

Antithrombotic therapy: use was nearly universal across the cohort.
Other medications: utilization varied by age, featuring beta-blockers, ACE inhibitors, and pulmonary vasodilators to differing extents.
Mental health considerations: anxiety disorders were clinically diagnosed in 34.1% of the population, rising to 48.1% among adults.

Implications and limitations

Significance: the network demonstrates capacity to generate robust, prospective, multi-institutional insights into Fontan circulation and associated care pathways.
Limitations: as a cross-sectional report describing baseline characteristics, causal inferences or long-term outcomes are not provided within this dataset.