Abstract P544: Post-COVID-19: Predictors of Pulmonary Fibrosis

Abstract

Introduction: From observational studies, it is known that some survivors of COVID-19 pneumonia have developed fibrotic pulmonary remodeling, restrictive lung abnormalities, associated with impaired exercise tolerance and poor quality of life at follow-up. Post-COVID-19 pulmonary fibrosis may be defined as the presence of persistent fibrotic changes identified on follow-up CT scans, such as traction bronchiectasis. It is important to identify the potential risk factors for the occurrence of pulmonary fibrosis in this context, although they have not yet been completely defined. Hypothesis: We hypothesize that lung fibrosis may be also a possible long-term consequence of COVID-19 pneumonia and the risk factors associated with the acute phase that enhance the risk of pulmonary sequelae, such as duration of hospitalization and intensive care stay, of high-flow oxygen support, and need for mechanical ventilation. Methods: We undertook a cohort study of COVID-19 survivors, that required supplemental oxygenation during the acute phase, who had been discharged from hospitals April 2020 to March 2022 in public hospitals of Curitiba/PR (BRAZIL). At 1-month and 6-month follow-up visit, survivors were interviewed with questionnaires symptoms, received a physical examination, sit-to-stand test, laboratory test ant chest CT scan was performed between two visits. The primary outcomes were persistent fibrotic changes, such as traction bronchiectasis, on follow-up chest CT. Multivariable adjusted logistic regression models were used to evaluate the risk factors of CT scan outcomes. Results: We followed 63 COVID-19 survivors with CT scan follow-up. The median age of patients was 52 years (±13.3) and 37 (58.7%) were women. The median CT scan follow-up time was 151 days (38-428). The median hospitalization time during acute phase was 13 (3-48) days. The proportion of patients with persistent dyspnoea, characterized by mMRC score of 1 or more, was 52 (82,5%). The proportion of patients with at least one fibrotic change on CT scan was 35 (55.6%), traction bronchiectasis was identified on 16 (25.4%). Hospitalization time during acute phase was associated with traction bronchiectasis, main persistent fibrotic change on CT scan (OR, 1.19; 95% CI:1.036, 1.207; p=0,004). Conclusion: In a follow-up, the duration of hospitalization COVID-19 acute phase was associated with higher odds of traction bronchiectasis on chest CT follow-up.