Vascular Dysfunction Relates to Reduced Exercise Capacity, Quality of Life for Fontan Survivors

Published Sept. 24, 2016
Journal of the American Heart Association

Complex Fontan surgery saves lives for infants born with severe congenital heart defects. However, as survivors grow into their adolescent and young adult years, increased arterial stiffness and decreased endothelial function appear to contribute to reduced aerobic capacity, physical activity, and quality of life.

In a cross-sectional study of 60 Fontan survivors, a research team led by Bryan Goldstein, MD, and Andrew Redington, MD, at Cincinnati Children’s, along with colleagues from Lurie Children's Hospital, evaluated patient capacity for exercise while tracking endothelial function and arterial stiffness. The team also examined quality of life measures.

In all cases, worse vascular measures were associated with worse functional measures.

This study is part of ongoing efforts to develop methods to prevent multisystem organ dysfunction among Fontan survivors. As patients reach adulthood, many develop “failing Fontan physiology,” which results from chronic exposure to low cardiac output and high central venous pressure.

“These results suggest that vascular function parameters could be important biomarkers of decreased functional performance. Furthermore, although these data cannot demonstrate a causal relationship, it is possible that abnormal vascular function itself is a determinant of functional performance and thus a potential therapeutic target to modify the inevitable functional decline observed in adolescent and young adult Fontan survivors,” the co-authors stated.

Early identification of Fontan patients at risk for failing physiology might allow for interventions to reduce the likelihood or to delay the rate of progression to symptomatic Fontan failure and the need for Fontan revision, conversion, or heart transplantation, the authors say.

The next step will be deeper studies to understand the cause–effect relationship between vascular function and functional outcomes.

These scatterplots compare vascular function parameters with measures of exercise performance. Peripheral arterial tonometry–derived baseline pulse amplitude vs. ventilatory equivalents of carbon dioxide at anaerobic threshold (A). Flow mediated vasodilation–derived reactive hyperemia index vs. percentage of predicted peak oxygen consumption (B).

Click image to enlarge.

PAT-derived augmentation index at 75 beats per minute vs. percentage of predicted peak VO2 (C). Pulse wave analysis–derived augmentation index vs. peak VO2 (D). In each case, there was a significant correlation between vascular and exercise measures. Each plot shows regression line (red) and 95% confidence interval (blue dotted lines).

Click image to enlarge.

Citation

Goldstein BH, Urbina EM, Khoury PR, Gao Z, Amos MA, Mays WA, Redington AN, Marino BS. Endothelial Function and Arterial Stiffness Relate to Functional Outcomes in Adolescent and Young Adult Fontan Survivors. J Am Heart Assoc. 2016 Sep 24;5(9).

A photo of Bryan Goldstein.

Bryan Goldstein, MD

Andrew Redington, MD