Home-based Cardiovascular Rehabilitation in Young Patients With Congenital Heart Disease: the "Muscle Your Heart" Program

Inclusion Criteria: * Indication for home cardiovascular rehabilitation given by the referring cardiologist as part of routine care. * Follow-up for congenital heart disease in the ACC-CHD classification. * Patient aged 8 to 25 years at the time of inclusion. * Consent of the adult patient or the parents or legal guardians of the minor patient. * Social security affiliation (excluding AME). * VO2max and/or SV1 \< -1.64 z-score for patients aged 8 to 17 years or VO2max \< 80% and/or SV1 \< 55% of theoretical VO2max for patients aged 18 to 25 years Exclusion Criteria: * Unstable and/or severe heart failure: severe heart failure (NYHA functional class IV), recent decompensated heart failure requiring hospitalisation and/or any significant change in medication (\< 3 months before inclusion), systolic ventricle dysfunction (left ventricular or systemic ventricular ejection fraction \< 50%). * Severe hypoxemia: pulse oxygen saturation (SpO2) at rest \< 85%, and/or SpO2 at exercise \< 80%, and/or patient requiring oxygen therapy. * Pulmonary hypertension as defined by the 2020 ESC guidelines, whatever the aetiology. * Significant systolic right ventricle (sRV) hypertension (Srv pressure \> 50% of systemic systolic pressure). * Uncontrolled arrhythmia: symptomatic arrhythmia treated or untreated at rest and/or during exercise, treated arrhythmia with sustained supraventricular or ventricular tachycardia on ECG monitoring or during exercise and/or CPET, occurrence or aggravation of any supraventricular or ventricular arrhythmia during exercise and/or CPET. * Advanced atrioventricular block (degree 2 or 3), occurrence or aggravation of any conduction disorder during exercise and/or CPET. * Uncontrolled arterial hypertension at rest (blood pressure at rest during the consultation \> 140/90 mmHg in adults, \> 95th percentile in children). * Acute or recent myocarditis and pericarditis (\< 3 months). * Symptomatic aortic or subaortic stenosis (mean gradient \> 50 mmHg). * Non-corrected coarctation of the aorta (surgical or catheter-based repair) with a clinical systolic gradient \> 20 mmHg. * Dilatation of the aorta (aortic root \> 40 mm in adults, \> 2 z-score in children) (http://www.parameterz.com/sites/aortic-root) except in the case of repaired CHD with dilatation of the aorta inherent in the malformation and without risk of aortic dissection (tetralogy of Fallot, transposition of the great vessels, pulmonary atresia IVC, common trunk artery). * Severe obstructive hypertrophic cardiomyopathy. * Acute systemic disease. * Recent intracardiac thrombus (\< 3 months), embolism or thrombophlebitis. * Inability to follow instructions and/or home rehabilitation and/or answer questionnaires, as determined by the investigator. * Absolute contraindications for CPET: fever, uncontrolled asthma, respiratory failure, acute myocarditis or pericarditis, uncontrolled arrhythmias causing symptoms or hemodynamic compromise, uncontrolled heart failure, acute pulmonary embolus or pulmonary infarction, and patients with mental impairment leading to inability to cooperate. * Inability to undergo the physical intervention: inability to physically exercise, any invasive medical intervention occurring within 6 months preceding the inclusion or scheduled during the 3-month study period (such as cardiac surgery, catheter-based intervention, orthopedic surgery, chemotherapy for cancer, or any other significant medical treatment or intervention, as determined by the investigator). * For female patients: pregnancy, planning to become pregnant, or breastfeeding woman following questioning of the patient. * Any other clinical and/or pharmacological treatment that is believed to interfere with the study or the optimal clinical care. * Patients deprived of their liberty due to ongoing legal procedure, adult patients under guardianship or curatorship, or unable to personally express their consent. * Patients who have benefited from cardiovascular rehabilitation in the 12 months preceding inclusion. * Patient participating or wishing to participate in any interventional clinical research (drug trial, medical device, non-drug trial).