Abstract 13536: Vascular Function is Predictive of Functional Outcomes in Adolescent and Young Adult Fontan Survivors
Introduction: Fontan survivors demonstrate diminished vascular function and functional outcomes. The relationships between measures of vascular function and functional outcomes have not been established.
Methods: Cross-sectional single-institution study of Fontan survivors ages 8-25 years. Multimodality assessment of endothelial function (reactive hyperemia index [RHI] and flow mediated dilation [FMD]) and arterial stiffness (augmentation index [AI] and baseline pulse amplitude [BPA]) was performed with peripheral arterial tonometry (PAT), brachial FMD and pulse wave analysis (PWA). Aerobic capacity was determined using cardiopulmonary exercise testing with cycle ergometry and a ramp protocol. Quality of life (QOL) was assessed using the pediatric QOL inventory (PedsQL) and physical activity (PA) was assessed using the PA Questionnaire (PAQ). Vascular measures served as predictor variables while functional outcome measures served as outcome variables. Bivariate predictors (p<0.1) were candidates for inclusion in multivariable models. Model development utilized linear regression and ordered logistic regression techniques.
Results: Sixty patients (52% male) completed the protocol with a mean age of 13.9 ± 4.1 years and duration of Fontan circulation of 9.9 ± 4.2 years. Maximal (max) exercise was achieved in 54 subjects with mean peak and %-predicted oxygen consumption (VO2) of 27.8 ± 7.6 ml/kg/min and 71.0 ± 21.2%, respectively. FMD-RHI (p<0.05) was associated with VO2 at anaerobic threshold (AT, R2 0.33). PAT-BPA (p<0.05) was associated with the ratio of minute ventilation to carbon dioxide at AT (R2 0.40). FMD-RHI, PAT-AI and PWA-AI (p<0.05) were associated with max VO2 (R2 0.36-0.53), %-predicted max VO2 (R2 0.40-0.56) and max O2 pulse (R2 0.26-0.31). PAT-AI and PAT-BPA (p<0.05) were associated with PedsQL total (R2 0.19-0.34) and physical heath summary score (R2 0.36-0.41). FMD max and PAT-BPA (p<0.05) were associated with PAQ score (R2 0.33-0.38).
Conclusions: Increased arterial stiffness and decreased endothelial function are associated with lower aerobic capacity, QOL and physical activity in adolescent and young adult Fontan survivors. Vascular dysfunction may be an important target for future therapeutic trials.
- Fontan physiology
- Endothelial function
- Exercise tests and training
- Quality of life
- Adult congenital heart disease
Author Disclosures: B.H. Goldstein: None. E.M. Urbina: None. P.R. Khoury: None. Z. Gao: None. M.A. Amos: None. W.A. Mays: None. A. Redington: None. B.S. Marino: None.
- © 2015 by American Heart Association, Inc.