Long-Term Lung Abnormalities Associated with COVID-19 Pneumonia

In the third year of the SARS-CoV-2 pandemic, much has been learned about the long- term effect of COVID-19 pneumonia on the lungs. Approximately one-third of patients with moderate-to-severe pneumonia, especially those requiring intensive care therapy or mechanical ventilation, have residual abnormalities on chest CT one year after presentation. Abnormalities range from parenchymal bands to bronchial dilation to frank fibrosis. Less is known about the long-term pulmonary vascular sequelae, but there appears to be a persistent, increased risk of venothromboembolic events in a small cohort of patients. Finally, the associated histologic abnormalities resulting from SARS- CoV-2 infection are similar to those of patients with other causes of acute lung injury.