Exercise training in congenital heart disease: is it effective and safe and does it improve quality of life

In children/young adults with congenital heart disease (ConHD), aerobic fitness
may be reduced, which may lead to an inactive lifestyle. Poor fitness and an
inactive lifestyle have been associated with increased risk of cardiovascular
disease and death, and poorer health related quality of life (HRQOL). Exercise
training programs may improve fitness and survival, and may reduce ventricular
size and neurohormonal activation. Exercise training has improved fitness in
small groups of patients with ConHD. Participation in sports activities /
exercise training has been recommended. However, information on effectiveness
and safety of exercise programs for this population is limited. This is
particularly true for lesions with right ventricular (RV) loading
abnormalities and/or for single ventricle lesions, in which exercise physiology
differs from LV disease states. This has prevented patients from participation
in sports. Furthermore, for these reasons adherence to current (Dutch Heart
Foundation) exercise training (rehabilitation) guidelines for ConHD patients is
poor. For ConHD, patient groups with right ventricular loading abnormalities or
single ventricles are important and additional knowledge is required for
adequate treatment.
We hypothesize that exercise training will a) improve aerobic fitness, b) will
not result in adverse remodeling (increase in ventricular size, neurohormonal
activation) and/or decline of ejection fraction, c) will increase daily
activity levels and d) will improve HRQOL and psychosocial functioning.

Objectives:
Medical: What is the effect of an exercise training program in children and
young adults (up to 20 years of age) who have undergone treatment for ConHD
(tetralogy of Fallot or Fontan procedure) on: a) aerobic fitness, b)
ventricular size, neurohormonal activation, ventricular ejection fraction and
c) the level of daily activity
Psychological: 1) What is the effect of an exercise training program in these
patients on a) health related quality of life and b) psychosocial functioning.

In 80 patients with Tetralogy of Fallot and 80 with Fontan circulation (ages 12
- 20 years) 40 patients from each category will be randomized to undergo a 3
months aerobic training program. The others will serve as controls. All
patients will undergo detailed cardiological and psychological assessment
before and after the 3 month period. This evaluation includes clinical
examination, 24 hour ECG, echocardiography, MRI to assess ventricular volumes
and ejection fraction, graded exercise testing with assessment of oxygen uptake
and work load, 48-hour activity monitoring (accelerometry-based), blood N
Terminal-pro Brain Natriuretic Peptide level, and standardized questionnaires
and semi-structured interview to assess HRQOL.

Exercisetraining, 3 times a week, for 1 hour /training, aerobic level (target
heart rate 60 % of maximal heartrate during exercise), for a 3 month period.

All clinical examinations are the same as are routinely performed during
follow-up of patients operated for tetralogy of Fallot or those who have
undergone the Fontan procedure, including dobutamine stress MRI.
For the purpose of the research proposal examinations will be clustered (T0
assessment), and will be repeated after 3 months (T1 assessment).
Standardized questionnaires and semi-structured interview to assess HRQOL are
only performed for research purposes.
A standard history, physical examination and ECG are performed. The patient is
subjected to an exercise test. After a 30 min. rest blood is drawn. Cardiac MRI
is performed. psychological examination is performed by means of standardized
questionnaires and a semi-structured interview. At the end of the visit
instructions on the 24-hour ECG and activity-monitor will be given. All
examinations will be performed at the same day, unless the patient prefers
otherwise. The total duration of these examinations is 5 hours.
Half of the patients will also perform aerobic exercise training at submaximal
level for 3 months. This is training of moderate intensity level. In small
comparable patient groups, no adverse effects have been reported. Positive
effects (increase in exercise performance, activuty level) have been reported.
All research results will be coded in a source document and will be stored in a
database. Bodily fluids will be given the same code. Of each participant 2 X
500 microliter blood will be kept for possible future use.
Burden and risk are similar to those of regular clinical procedures and
follow-up.