Echocardiographic Findings in Adolescents Presenting for Sports Clearance Following COVID-19

Background: Multiple studies have investigated cardiovascular effects associated with COVID-19 in collegiate and professional athletes. The incidence of cardiovascular abnormalities in adolescents seeking a return to sports following COVID-19 is not well known. We performed a comprehensive analysis of clinical and subclinical function in a cohort of post-COVID individuals seeking clearance for sports participation. We hypothesized that adolescent athletes after COVID-19 would have subclinical functional abnormalities.

Methods: We reviewed outpatient transthoracic echocardiograms obtained between 11/01/2020 and 12/31/2020 for clearance for return to activity/sports of patients aged 12-18 with a history of mild or moderate COVID infection (COVID group). Adolescents from the pre-COVID era with complaints of chest pain, shortness of breath, palpitations, or syncope served as controls (pre-COVID group). Conventional echocardiographic metrics were abstracted from clinical reports; two investigators retrospectively used speckle tracking echocardiography to obtain left ventricular global longitudinal strain (LV GLS), LV global circumferential strain (GCS), right ventricular global longitudinal strain (RV GLS), and RV free wall strain (FWS). Upper limit of normal for GLS was -18%. Wilcoxon rank-sum test was used to evaluate differences between the groups, and Spearman’s rho was used to evaluate correlations. Multivariable linear regression following multiple imputation of minimal missing data was performed to evaluate associations.

Results: Thirty-eight COVID and 36 pre-COVID subjects were enrolled. There was no significant difference in the groups’ age and gender distributions (Table 1). Median time since COVID diagnosis in that cohort was 33.5 days (IQR 22 – 64). Symptoms were reported in 68.4% of that group with a borderline or abnormal ECG in 23.7%; 1 patient had depressed left ventricular ejection fraction (LVEF) and associated abnormal strain, and 8 had abnormal LV GLS despite normal LVEF based on our cut-off of -18%. The COVID group had decreased LV GLS, LV GCS, RV FWS, and RV GLS in comparison to the pre-COVID group (Table 1, Figure 1).

Within the COVID cohort, controlling for age and gender, neither abnormal ECG nor presence of symptoms was associated with abnormal LV GLS or GCS. Time since COVID diagnosis was not associated with conventional echocardiographic or strain metrics. The COVID group continued to have worse LV GCS and RV GLS after controlling for age and gender; LV GLS and RV FWS no longer correlated with COVID status in multivariable analysis.

Conclusion: In adolescents with prior mild or moderate COVID illness, ventricular function by conventional metrics is not categorically different from those without a COVID history. However, differences in myocardial strain suggest subclinical dysfunction. Future studies should elucidate whether these myocardial strain abnormalities persist and whether they are predictive of adverse outcomes in these patients.