Galectin-3 in single ventricle physiology: insights into fibrosis and functional impairment after Fontan procedure

Galectin-3 (Gal-3) is a biomarker associated with myocardial fibrosis, a key factor in the dysfunction of the functionally single ventricle (FSV) in patients after the Fontan procedure. This study aimed to evaluate the relationship between serum Gal-3 levels and echocardiographic and cardiopulmonary exercise parameters in this population.

Thirty-seven patients (23 males, 14 females) with Fontan circulation were included. All underwent speckle-tracking echocardiography (STE), cardiopulmonary exercise testing (CPET), and serum Gal-3 measurement using ELISA. Correlations between Gal-3 and clinical, echocardiographic, and CPET parameters were analyzed.

Gal-3 levels correlated positively with patient age and time since Fontan completion (p < 0.05). No significant associations were found between Gal-3 and ejection fraction, global longitudinal strain (GLS), or free wall strain. However, Gal-3 showed a significant correlation with the transmural strain gradient (p < 0.05). No association was observed between Gal-3 and CPET parameters, including peak VO₂.

Galectin-3 may reflect fibrotic remodeling of the FSV, as suggested by its correlation with the transmural strain gradient. The absence of a relationship with exercise capacity highlights the complexity of Fontan-related dysfunction. Gal-3 shows promise as a noninvasive biomarker of myocardial fibrosis in this unique patient group.