Padalino MA; Pediatric and Congenital Cardiac Surgery, University of Padova, Padova, Italy.;
Ponzoni M; Reffo E; Azzolina D; Cavaliere A; Puricelli F; Cabrelle G; Bergonzoni E; Cao I;Gozzi A; Castaldi B; Vida V; Di Salvo G;
Cardiology in the young [Cardiol Young] 2024 Oct 30, pp. 1-10.
Date of Electronic Publication: 2024 Oct 30.
Objectives: The functional roles of ventricular dominance and additional ventricular chamber after Fontan operation are still uncertain. We aim to assess and correlate such anatomical features to late clinical outcomes.
Methods: Fontan patients undergoing cardiac MRI and cardiopulmonary exercise test between January 2020 and December 2022 were retrospectively reviewed. Clinical, cardiac MRI, and cardiopulmonary exercise test data from the last follow-up were analysed.
Results: Fifty patients were analysed: left dominance was present in 29 patients (58%, median age 20 years, interquartile range:16-26). At a median follow-up after the Fontan operation was 16 years (interquartile range: 4-42), NYHA classes III and IV was present in 3 patients (6%), 4 (8%) underwent Fontan conversion, 2 (4%) were listed for heart transplantation, and 2 (4%) died. Statistical analysis showed that the additional ventricular chamber was larger (>20 mL/m 2 ) in patients with a right dominant ventricle ( p = 0.01), and right dominance was associated with a higher incidence of post-operative low-cardiac output syndrome ( p = 0.043). Left ventricular dominance was associated with a better ejection fraction ( p = 0.04), less extent of late gadolinium enhancement ( p = 0.022), higher metabolic equivalents ( p = 0.01), and higher peak oxygen consumption ( p = 0.033). A larger additional ventricular chamber was associated with a higher need for post-operative extracorporeal membrane oxygenation support ( p = 0.007), but it did not influence functional parameters on cardiac MRI or cardiopulmonary exercise test.
Conclusions: In Fontan patients, left ventricular dominance correlated to better functional outcomes. Conversely, a larger additional ventricular chamber is more frequent in right ventricular dominance and can negatively affect the early post-Fontan course.