Introduction: Fontan palliation results in favorable short-term outcomes but limited exercise tolerance and poor quality of life (QOL) years after completion. Vessel narrowing and power loss in Fontan survivors results in worse exercise tolerance.
Hypothesis: Poor Fontan geometry, computational fluid dynamics (CFD), and ventricular function is associated with worse QOL.
Methods: Fontan survivor >12 yrs from a single center who completed a cardiac magnetic resonance (CMR) and supine metabolic exercise stress test were included. CMR-derived variables included Fontan geometry, hemodynamics and ventricular function. Geometry was analyzed by vascular modeling toolkit. CFD simulations were performed to quantify normalized power loss at rest and anaerobic threshold, pressure drop and resistance across the Fontan. QOL was assessed by subject completion of the Pediatric Quality of Life Inventory (PedsQL) at the time of CMR or after a baseline CMR [Follow-up (FU) QOL]. Comparisons were made between CMR and CFD parameters with QOL: longitudinal association CMR at baseline and FU QOL; cross sectional association of CMR and QOL, and cross sectional association of exercise CMR with QOL. Linear regression was used for univariate and multivariate analyses.
Results: We included 77 Fontan pts: median age 18 (IQR 13-20) yrs; Fontan type (85% lateral tunnel/15% extracardiac); median time from Fontan completion 16 (IQR 13-20) yrs. Longitudinal data was available for 48 patients: median time between CMR and QOL FU was 8 (7.0-9.4) yrs. Median PedsQL Total score was 80 (IQR 67-88). Table 1 delineates multivariate models.
Conclusions: In Fontan survivors greater normalized power loss, maximal pressure drop and resistance across the Fontan, and lower cardiac index are associated with worse QOL. The impact of Fontan geometry, CFD, and ventricular function on QOL suggests that surgical planning to optimize the Fontan may improve later QOL. A prospective multicenter trial is warranted.