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Exercise capacity improves after transcatheter closure of the Fontan fenestration in children
Wayne A Mays1, William L Border, Sandra K Knecht
1Division of Cardiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA. wayne.mays@cchmc.org
Insights
Transcatheter fenestration closure in children with Fontan palliation significantly improves arterial oxygen saturation (O(2)Sat) and aerobic capacity. This procedure enhances exercise performance despite immediate post-closure reductions in cardiac output.
Area of Science:
- Pediatric Cardiology
- Congenital Heart Disease
- Cardiovascular Physiology
Background:
- The Fontan procedure is a palliative surgery for single-ventricle congenital heart defects.
- Fenestration closure is a common intervention post-Fontan palliation.
- Evaluating the impact of fenestration closure on exercise capacity is crucial for patient management.
Purpose of the Study:
- To assess changes in aerobic capacity, exercise capacity, and arterial oxygen saturation (O(2)Sat) in children post-transcatheter Fontan fenestration closure.
- To compare pre- and post-intervention exercise parameters.
Main Methods:
- An observational study design was employed.
- Exercise parameters including working capacity, exercise duration, oxygen consumption (VO(2)), and arterial O(2)Sat were measured before and after transcatheter fenestration closure.
- Patients underwent standardized exercise testing, with cycle ergometry or Bruce treadmill protocols used based on age.
Main Results:
- Twenty pediatric patients (mean age 11.4 years) were evaluated.
- Following fenestration closure, arterial O(2)Sat significantly increased (89% to 95% at rest, 82% to 92% during exercise).
- Exercise duration, maximal VO(2), indexed maximal VO(2), and total working capacity all showed significant improvements.
Conclusions:
- Transcatheter fenestration closure effectively improves exercise arterial O(2)Sat and aerobic capacity in children with univentricular hearts post-Fontan palliation.
- These benefits are observed despite a documented decrease in resting cardiac output immediately after the procedure.
- The findings support fenestration closure as a beneficial intervention for enhancing functional capacity in Fontan patients.
Objectives:
This study evaluated the aerobic capacity, exercise capacity, and arterial oxygen saturation (O(2)Sat) in children before and after transcatheter Fontan fenestration closure.
Design:
Observational study comparing exercise parameters and hemodynamics before and after transcatheter fenestration closure in Fontan patients.
Outcome Measures:
Working capacity, exercise duration, oxygen consumption (VO(2)), and arterial O(2)Sat were evaluated during aerobic exercise.
Results:
Twenty patients (mean age 11.4 years) underwent standardized exercise testing before and after fenestration closure. Twelve patients underwent cycle ergometry testing (mean age 14.8 years) (group 1), and eight younger patients (mean age 6.4 years) underwent Bruce treadmill testing (group 2). The same exercise protocol was used in each patient before and after fenestration closure (interval between tests: 118 +/- 142 days). Immediately following fenestration closure at cardiac catheterization, cardiac index decreased (3.0 to 2.1 L/minute/m(2)) and Fontan pressure increased (11 +/- 2 to 12 +/- 2 mm Hg) with an increased arterial saturation (92 to 96%) (P < .001). The total group demonstrated no significant change in pre- and postclosure maximal heart rates (164 +/- 21 and 169 +/- 19 bpm). Rest and exercise O(2)Sat increased (89 and 82 to 95 and 92%) (P < .0001). Exercise duration increased (7.7 +/- 1.9 to 9.2 +/- 2.4 minutes) (P < .0005). Maximal VO(2), indexed maximal VO(2), and total working capacity in kilopond-meters (kpm) increased (1.2 +/- 0.5, 27 +/- 7 and 2466 +/- 1012 to 1.3 +/- 0.4 L/minute, 31 +/- 9 mL/kg/minute and 2869 +/- 1051 kpm, respectively) (P < .005).
Conclusion:
In children with a univentricular heart after Fontan palliation, transcatheter fenestration closure improves exercise arterial O(2)Sat and aerobic capacity despite a restricted resting cardiac output documented by catheterization immediately after the closure procedure.
