Echocardiographic Assessment of Atrial Function in Patients With Fontan Palliation: Feasibility, Reproducibility, and Prognostic Implications

Background

Atrial strain provides a global assessment of left heart diastolic function in patients with biventricular circulation, and it is used for risk stratification. However, the role of atrial strain imaging for risk stratification in patients with Fontan palliation has not been studied, and this is likely related to the complex anatomy of the pulmonary venous atrium in this population. The purpose of this study was to assess the feasibility and reproducibility of echocardiographic indices of pulmonary venous atrial function and their relationship to clinical outcomes.

Methods

This is a retrospective cohort study of adults with Fontan palliations who underwent transthoracic echocardiogram at Mayo Clinic (2003-2023). Atrial reservoir strain was used as a measure of global atrial function and was assessed using speckle tracking imaging. The relationship between atrial reservoir strain and death/transplant was assessed using multivariable Cox regression analysis.

Results

Of 518 patients, the assessment of atrial strain was feasible in 411 (79%), with modest intraobserver and interobserver reproducibility (intraclass correlation: 0.83, 95% confidence interval [CI]: 0.76-0.89 and intraclass correlation: 0.81, 95% CI: 0.74-0.87, respectively). The correlates of atrial dysfunction (worse atrial reservoir strain) were older age, systemic ventricular systolic dysfunction, and history of atrial fibrillation. There was a 13% decrease in the risk of death/transplant for every 5% increase in atrial reservoir strain (adjusted hazard ratio: 0.87, 95% CI: 0.72-0.92, P = 0.02) after adjustment for demographic indices, surgical/anatomic indices, and comorbidities/end-organ function.

Conclusions

Echocardiographic assessment of pulmonary venous atrial strain was feasible and reproducible and can be used for risk stratification in adults with Fontan palliation.