Echocardiographic Indices of Ventricular Systolic Function in Adults With Fontan Palliation: Feasibility, Reproducibility, and Prognostic Implications.

BACKGROUND

The assessment of systemic ventricular systolic function in patients with Fontan palliation is challenging because of anatomic differences in ventricular morphology. The purpose of this study was to assess the feasibility and reproducibility of echo-derived systolic function indices as well as their relationship to clinical outcomes in adults with Fontan palliation.

METHODS

This work is a retrospective cohort study of adults with Fontan palliations without significant valve dysfunction who underwent echocardiography at the Mayo Clinic from 2003 to 2023. We excluded patients with unknown/indeterminate ventricular morphology and those with at least moderate regurgitation of the atrioventricular or the semilunar valve, because these factors could potentially confound assessment ventricular systolic function. Three echo indices were measured from a single imaging window (apical 4-chamber view): ejection fraction (Echo_EF), fractional area change (Echo_FAC), and longitudinal strain (Echo_LS). Cardiac magnetic resonance imaging (CMRI) reports were reviewed for those patients who had it performed. The relationship between echo-derived systolic function indices and death/transplant was assessed using multivariable Cox regression analysis.

RESULTS

The study comprised of 512 patients (369 with systemic left ventricle [72%] and 143 with systemic right ventricle [28%]). Assessment of echo indices was feasible in > 87% of the patients, showed good reproducibility, and had a modest correlation with CMRI_EF. All 3 echo-derived indices were lower in patients with morphologic right ventricle compared with left ventricle and were associated with death/transplant regardless of ventricular morphology. Echo_EF < 45%, Echo_FAC < 30%, or Echo_LS < 15% were the optimal cutoff points to identify patients at highest risk of death/transplant.

CONCLUSIONS

Multiparametric assessment of ventricular systolic function using echocardiography was feasible and reproducible in patients with Fontan palliation and could be obtained from a single imaging window. Further studies are required to determine whether clinical decision-making based on these echo-derived systolic function indices would improve clinical outcomes in this population.