Subclinical abnormalities of systolic and diastolic function in longitudinal echocardiography after mild initial COVID illness

Cardiac inflammatory involvement is an increasingly recognized sequelae of COVID-19 disease. The aim of this study was to evaluate the subclinical patterns and evolution of cardiac abnormalities using transthoracic echocardiography (TTE) in patients with mild initial COVID-19 illness.

343 infected individuals (163 males; age 44 (interquartile range, IQR 35-52) years) underwent serial TTE assessments at a median of 109 (interquartile range (IQR), 77–177) and 327 (276-379) days after infection. Compared to non-COVID infected controls (n=94, male n=49), baseline systolic (LVEF, TAPSE) and diastolic function (e’, a’, E/e’) were significantly different in infected participants (p<0.05 for all). Compared to baseline assessments, there was a reduction in global longitudinal strain (GLS), and an increase in E wave, E/A ratio and E/e’ at follow up. At baseline symptomatic participants had lower LVEF and TAPSE, increased IVRT, e’ and E/e’. At follow-up symptomatic patients had lower LV end-diastolic diameter (LVEDd). Symptoms were independently associated with E/e’ at baseline (OR (95%CI) 1.45 (1.12-1.87), p=0.005). At follow up symptoms were associated LVEDd (OR (95%CI): 0.91 (0.86-0.96), p<0.001), followed by the model that also included NTproBNP (OR (95%CI): 1.01 (1.00-1.01), p=0.047). There were significant associations for GLS and troponin, and E/e’ with CRP and NTproBNP at baseline.

In the present cohort of COVID-19 infected individuals with mild initial illness, echocardiographic measurements reveal significant yet subclinical differences in systolic and diastolic function compared to controls, as well as between individuals with cardiac symptoms and those without. All the measured differences were small in magnitude, thus unlikely detectable clinically on an individual level.