Cardiopulmonary function in paediatric post-COVID-19: a controlled clinical trial

Abstract

Recently, the importance of post-COVID-19 in children has been recognized in surveys and retrospective chart analysis. However, objective data in the form of cardiopulmonary exercise test as performed in adults suffering from this condition are still lacking. This study aimed to investigate the cardiopulmonary effects of post-COVID-19 on children and adolescents. In this cross-sectional study (the FASCINATE study), children fulfilling the criteria of post-COVID-19 and an age- and sex-matched control group underwent cardiopulmonary exercise testing on a treadmill and completed a questionnaire with regard to physical activity before, during and after the infection with SARS-CoV-2. We were able to recruit 20 children suffering from post-COVID-19 (mean age 12.8 ± 2.4 years, 60% females) and 28 control children (mean age 11.7 ± 3.5 years, 50% females). All participants completed a maximal treadmill test with a significantly lower $\dot{\text{V}}{\text{O}}_2\text{peak}$ in the post-COVID-19 group (37.4 ± 8.8 ml/kg/min vs. 43.0 ± 6.7 ml/kg/min. p = 0.019). This significance did not persist when comparing the achieved percentage of predicted $\dot{\text{V}}{\text{O}}_2\text{peak}$ . There were no significant differences for oxygen pulse, heart rate, minute ventilation or breathing frequency. Conclusion: This is the first study to investigate post-COVID-19 in children using the cardiopulmonary exercise test. Although there was a significantly reduced $\dot{\text{V}}{\text{O}}_2\text{peak}$ in the post-COVID-19 group, this was not true for the percent of predicted values. No pathological findings with respect to cardiac or pulmonary functions could be discerned. Deconditioning was the most plausible cause for the experienced symptoms. Trial registration: clinicaltrials.gov, NCT054445531, Low-field Magnetic Resonance Imaging in Pediatric Post Covid-19-Full Text View-ClinicalTrials.gov. What is Known: • The persistence of symptoms after an infection with SARS-CoV 2, so-called post-COVID-19 exists also in children. • So far little research has been conducted to analyze this entity in the pediatric population. What is New: • This is the first study proving a significantly lower cardiopulmonary function in pediatric patients suffering from post-COVID-19 symptoms. • The cardiac and pulmonary function appear similar between children suffering from post-COVID-19 and those who don't, but the peripheral muscles seem affected.

Keywords: V ˙ O 2 peak ; Cardiopulmonary exercise testing; Exercise capacity; Fitness; Physical activity; Post-COVID.

Fig. 1

Median, as well as interquartile range, minimum and maximum of the $\dot{\text{V}}{\text{O}}_2\text{peak}$ between the children suffering from post-COVID-19 and the control group. The difference was significant

Fig. 2

Correlation between the rest period after infection with SARS-CoV-2 in weeks and the $\dot{\text{V}}{\text{O}}_2\text{peak}$