An Early Glenn Operation May be Associated with the Later Occurrence of Protein-Losing Enteropathy in Fontan Patients : Association of Early Glenn and Failing Fontan

Protein-losing enteropathy (PLE) and plastic bronchitis (PB) are major causes of long-term mortality after Fontan operation. The objective of this study was to determine early clinical risk factors before the onset of PLE and PB. In a cohort study, 106 Fontan patients between 2005 and 2013 were examined. A median of 5.3 (1.5-8.5) years later, follow-up questionnaires were used to group the patients in a PLE or PB group (n = 14) and a non-PLE/PB group (n = 92). Prevalence of PLE was 9.4% (n = 10) and of PB 3.8% (n = 4). At follow-up, five patients (4.7%) died of PLE or PB. Median age at death was 6.2 years (IQR 10.5, 95% CI 5.3-23.4). We observed no significant group differences in gender distribution (p = 0.73), ventricular morphology (p = 0.87), surgical technique (p = 0.64), conduit fenestration (p = 0.34), age at Fontan operation (p = 0.54), and need for diuretics (p = 0.56). Hypoplastic left heart syndrome was more frequent in the PLE/PB group 50 vs. 22.8% (p = 0.03) OR 3.4 (95% CI 1.1-10.8). The modified Glenn procedure was performed at a median age of 4 months (IQR 4.0) in the PLE/PB group versus 8 months (IQR 8.0) in the non-PLE/PB group (p = 0.01). The early Glenn procedure and hypoplastic left heart syndrome may be associated with the development of PLE and PB.

Does exercise training improve cardiopulmonary fitness and daily physical activity in children and young adults with corrected tetralogy of Fallot or Fontan circulation? A randomized controlled trial

BACKGROUND

Many patients with congenital heart disease do not meet current public health guidelines to participate in moderate-to-vigorous physical activity for ≥60 minutes per day. They are less fit than their healthy peers. We hypothesized that exercise training would increase cardiopulmonary fitness and daily physical activity in these patients. We therefore assessed effects of an exercise training program on cardiopulmonary fitness and daily physical activity in patients with corrected tetralogy of Fallot (ToF) or Fontan circulation.

METHODS

In a multicenter prospective controlled trial, patients with ToF or Fontan circulation (age 10-25 years) were randomized, 56 patients to the exercise group and 37 to the control group. The exercise group participated in a 12-week standardized aerobic exercise training program. The control group continued lifestyle as usual. Cardiopulmonary exercise testing and activity measurements were performed before and after 12 weeks.

RESULTS

Peak oxygen uptake increased in the exercise group by 5.0% (1.7 ± 4.2 mL/kg per minute; P = .011) but not in the control group (0.9 ± 5.2 mL/kg per minute; P = not significant). Workload increased significantly in the exercise group compared with the control group (6.9 ± 11.8 vs 0.8 ± 13.9 W; P = .047). Subgroup analysis showed a significant increase in pre-to-post peak oxygen uptake in the exercise group of ToF patients but not in the exercise group of Fontan patients. Percentage of measured time spent in moderate-to-vigorous activity at baseline was 13.6% ± 8.6%, which did not significantly change after training.

CONCLUSIONS

Aerobic exercise training improved cardiopulmonary fitness in patients with ToF but not in patients with Fontan circulation. Exercise training did not change daily physical activity.

Physical activity levels in children and adolescents are reduced after the Fontan procedure, independent of exercise capacity, and are associated with lower perceived general health

OBJECTIVES

To determine physical activity levels in paediatric patients who underwent the Fontan procedure, and their relationship to functional status and exercise capacity.

STUDY DESIGN

We studied 147 patients (ages 7-18 years) at a median of 8.1 years after Fontan, as part of the Pediatric Heart Network cross-sectional study of Fontan survivors. Assessment included medical history, self-reported physical activity, parent-completed Child Health Questionnaire (CHQ), cardiopulmonary exercise testing and physical activity level measured by accelerometry (MTI Actigraph).

RESULTS

Measured time spent in moderate and vigorous activity was markedly below normal at all ages, particularly in females, and was not significantly related to self-reported activity levels, or to maximum Vo2, Vo2 at anaerobic threshold or maximum work rate on exercise testing. Lower measured activity levels were significantly related to lower perceived general health but not to self-esteem, physical functioning, social impact of physical limitations or overall physical or psychosocial health summary scores. Reduced exercise capacity was more strongly related than measured activity levels to lower scores in general health, self-esteem and physical functioning.

CONCLUSIONS

Physical activity levels are reduced after Fontan, independent of exercise capacity, and are associated with lower perceived general health but not other aspects of functional status.

Exercise capacity and impact of exercise training in patients after a Fontan procedure: a review

After a successful Fontan procedure, children and adolescents should improve their exercise capacity. However, several studies have shown that these children have a reduced maximal oxygen consumption compared with healthy children. The lower exercise performance in these patients was mainly explained by a reduced cardiorespiratory functional capacity. However, it has recently been reported that the lower exercise performance may also be related to altered skeletal muscle function. Moreover, exercise training had a beneficial impact on several parameters related to exercise tolerance in these patients. The main studies supporting these observations are reviewed, with a focus on the physiological adaptation and limitation of the exercise performance as well as the benefits of exercise training in patients after a Fontan procedure.

Impact of exercise training on muscle function and ergoreflex in Fontan patients: a pilot study

BACKGROUND

Several studies have demonstrated persistent reduced exercise capacity in Fontan patients even after surgical intervention. The purpose of this study was to evaluate if the skeletal muscle function of these patients is abnormal, if it correlates with exercise tolerance and if it can be improved by exercise training.

METHODS

We evaluated the functional capacity of seven patients who underwent Fontan procedure (age:16+/-5 years, mean+/-SD) and seven healthy children (19+/-7 years) paired for age, sex, height and weight. Evaluation included pulmonary evaluation, neuromuscular function and exercise tolerance. Secondly, an 8-week exercise training program was performed by five of these patients.

RESULTS

The ergoreflex contribution to absolute diastolic blood pressure was higher (12.5+/-4.8 vs. 5.6+/-4.2 mmHg; p=0.04) in Fontan patients vs. healthy subjects whereas a trend was encountered regarding the ergoreflex contribution to absolute systolic blood pressure (9.0+/-7.0 vs. 0.4+/-9.0 mmHg; p=0.09). Furthermore, time to fatigue of the non-dominant forearm muscles was shorter in Fontan patients vs. healthy subjects (431+/-290 vs. 847+/-347 s; p=0.03). Following exercise training, there was a significant reduction of the ergoreflex contribution to absolute values of systolic blood pressure (9.8+/-0.9 vs. 0.3+/-2.7 mmHg; p<0.05). There was an association between muscle strength and VO2 peak in Fontan patients (upper limb: r=0.895; p<0.01; lower limb: r=0.838; p<0.05, respectively).

CONCLUSIONS

Skeletal muscle function in Fontan patients is abnormal which may have an impact in the reduced exercise tolerance encountered in these patients. Exercise training may have beneficial impacts on the skeletal muscle function in this population.

Post-exercise heart rate, blood pressure and oxygen uptake dynamics in pediatric patients with Fontan circulation

BACKGROUND

Post-exercise heart rate (HR) and oxygen uptake (V O(2)) recover more slowly in patients with the Fontan circulation, but little is known about the determinants of the delayed recovery.

PURPOSE

To evaluate the post-exercise cardiovascular dynamics and clinical profiles in these patients.

METHODS AND RESULTS

We studied 51 Fontan patients (14+/-4 years) (atriopulmonary connection, APC = 18 and total cavopulmonary connection, TCPC = 33) and compared the results with 34 patients after right ventricular outflow tract reconstruction (RVOTR) with identical exercise capacity and arterial baroreflex sensitivity (BRS) (15+/-4 years) and with 26 controls (14+/-4 years). There were no differences in post-exercise HR or VO2 declines between the Fontan and RVOTR groups. Although the systolic blood pressure (SBP) decline was delayed in the RVOTR group (p < 0.01), its early decline in the Fontan group was rapid and equivalent to that in controls. In Fontan patients, BRS had a great impact on early HR decline (p < 0.05) and early VO2 decline was determined by peak VO2, age and cardiac index (p < 0.05-0.001). TCPC and lower BRS were the main determinants of the slower SBP decline (p < 0.05). In another study of repeated paired exercise tests before and after Fontan operation, post-exercise SBP decline became greater after the operation (p < 0.07).

CONCLUSIONS

In the Fontan group, post-exercise HR and VO2 declines are markedly delayed and are determined by cardiac vagal nervous activity, exercise capacity and age, respectively. Despite identical impaired hemodynamics and exercise capacity, post-exercise SBP decline is greater in the Fontan group, especially after APC, than in the RVOTR patients.

Effects of aerobic exercise training in children after the Fontan operation

It was demonstrated that patients who have undergone the Fontan operation can safely undertake exercise training and that this results in an improvement in aerobic capacity. These findings suggest that aerobic training could be useful in the long-term management of these patients to optimize their cardiovascular fitness for more active lives.