Impaired cardiorespiratory fitness and endothelial function after SARS-CoV-2 infection in a sample of mainly immunocompromised youth.

This study aimed to compare cardiopulmonary fitness and endothelial function 6 months after hospital diagnosis in a sample mainly comprising immunocompromised patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection versus noninfected controls. Youth ( = 30; age: 14 yr; 60% females) with confirmed SARS-CoV-2 seen in a tertiary hospital of Sao Paulo, Brazil, were matched by propensity score based on BMI, age, sex, and pre-existing diseases with a control group who had not been tested positive for SARS-CoV-2 infection ( = 30; age: 15 yr; 50% females). Cardiopulmonary fitness (by means of a cardiopulmonary exercise test: CPET) and brachial flow-mediated dilation (%b-FMD) were assessed 3-6 mo after diagnosis. Patients were matched by propensity score based on BMI, age, sex and pre-existing diseases, if any, with a control group who had not been tested positive for SARS-CoV-2. Compared with controls, patients with COVID-19 showed reduced ventilatory anaerobic threshold (VAT) and peak exercise time and minute ventilation/maximum voluntary ventilation (V̇e/MVV) (all < 0.01). Brachial endothelial function variables were all adjusted for body surface area (BSA). Patients with COVID-19 had decreased %b-FMD (3.6 vs. 5.4; = 0.03) mean and positive flow ( = 0.02 and = 0.03, respectively) versus controls. Adjusted linear regression models exploring associations between CPET variables, %b-FMD and the potential predictors post-COVID-19 syndrome, number of symptoms, hospitalization, and COVID severity did not detect significant associations, except for total shear rate in hospitalization (coefficient: -65.07 [95%CI -119.5;-10.5], = 0.02). Immunocompromised and previously healthy children and adolescents with COVID-19 presented with impaired exercise capacity and endothelial dysfunction when compared with their noninfected counterparts, but the mechanisms remain unknown. COVID-19 appeared to impair recovery of exercise capacity and endothelial function in a sample mainly comprising immunocompromised patients, but the mechanisms are unknown. These findings support the need for preventive measures against COVID-19 in this vulnerable population and suggest the necessity of proper monitoring and treatment for these patients.