Evolution of Cardiopulmonary Fitness in Children With Congenital Heart Disease
Condition: Congenital Heart Disease
MeSH terms: Heart Diseases; Heart Defects, Congenital
Study type: Observational

Summary: 
      With an incidence of 0.8 %, congenital heart disease (CHD) is the leading cause of congenital
      anomalies at birth. Medical advances in CHD have transferred the mortality from childhood to
      adulthood and today there are more adults with CHD than children. After focusing on survival,
      more attention is being given to health-related quality of life and secondary prevention in
      this population where warning signals are launched on the risk of sedentary lifestyle,
      obesity, cardiovascular risk 1.

      The cardiopulmonary exercise test (CPET), which is a non-invasive and dynamic examination, is
      becoming the gold standard to the follow-up 2 of these patients by allowing to quantify
      disease severity, to evaluate the quality of life 3, to give important prognostic information
      on functional capacity and haemodynamic response 4, to facilitate a safe decision-making when
      prescribing exercise programmes and sport participation for these children with CHD 5.

      In this context, in a cross-sectional study from 2010 to 2015, the investigators evaluated
      the cardiopulmonary fitness of children with CHD by comparing them with healthy children 6.
      In this study, 496 children with CHD compared to 302 healthy children were included. It
      showed that maximum oxygen uptake (VO2max) and ventilatory anaerobic threshold (VAT) are
      decreased in CHD children compared to healthy children, clinical determinants of decreased
      VO2max have been defined for CHD children. This study was proposed, despite the
      cross-sectional nature, an average decrease in annual VO2max (0,84 ml/kg/min per year) to
      make pediatric and congenital cardiologist aware of the need to a regular follow up for these
      patients.

      In this new study, the main objective was to know the real evolution of VO2max in these
      patients from this same cohort, with a longitudinal design, by collecting a new CPET carried
      out between 2015 and 2020 and compared these results to healthy pediatric population.

      The secondary objectives were: to know the evolution of the VAT, to define the clinical
      determinants in relation to the annual decrease of the VO2max. And to describe the population
      lost to follow-up in this retrospective study which represents current practice.
    

Detailed description: 
      Longitudinal multi-center study from November 2010 to September 2020 in two pediatric CPET
      laboratories (center 1: M3C Regional Pediatric and Congenital Cardiology Centre, Montpellier
      University Hospital, France; center 2: Pediatric Cardiology and Rehabilitation Centre,
      Institut-Saint-Pierre, Palavas-Les-Flots, France).

      Two groups will be identify: CHD group and control group. The CHD group is made up of the
      children included in the first study6. From these 496 children with CHD, children with a
      second CPET more than one year from the first referral CPET were included. If several CPETs
      were performed in the follow-up, we retain the most distant CPET from the first. The patients
      included in the initial study were aged 5-18 years old and they were referred by their
      paediatric cardiologists to one of the two CPET laboratories after their annual medical
      check-up.

      The control group consisted of children referred for a nonsevere functional symptom linked to
      exercise (murmur, palpitation or dyspnoea) or for a medical sports certificate. These
      children were classified in the control group only after a completely normal check-up,
      including physical examination, ECG, echocardiography and spirometry. Children with any
      chronic disease, medical condition (cardiac, neurological, respiratory, muscular or renal),
      or medical treatment and those requiring any further specialised medical consultation were
      not eligible. We included controlled children from 2015-2020 period who will be added to the
      controlled patients of the initial study6. These patients only had one CPET.

      The main objective was to describe the annual evolution in VO2max for patients with CHD
      compared to control children.

      Secondary obectives were :

        -  describe the annual evolution of ventilatory anaerobic threshold (VAT) for patients with
           CHD compared to control children.

        -  define the clinical determinants in relation to the annual decrease of the VO2 max.

        -  describe the population lost to follow-up in this retrospective study which represents
           current practice
    

Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        -  Children with congenital heart disease with 2 CPET separated at least by 1 year

          -  Controlled children with completely normal check-up, including physical examination,
             ECG, echocardiography and spirometry
      
Keywords: Congenital heart disease; VO2max; Cardio-pulmonary exercise test