Long-term outcome of pulmonary involvement in patients with coronavirus disease 2019: The role of high-resolution computed tomography and functional status – A prospective single-center observational study

Abstract

BACKGROUND: Since its first outbreak, coronavirus disease 2019 (COVID-19) has led to a great deal of published literature highlighting the short-term determinants of morbidity and mortality. Recently, several studies have reported radiological and functional sequelae from 3 months to 1 year among hospitalized COVID-19 survivors; however, long-term (more than 1 year) respiratory consequences in this population remain to be evaluated. OBJECTIVE: To assess the long-term radiological and pulmonary function outcomes of patients with COVID-19 2 years after resolution of the initial infection. METHODS: Hospitalized COVID-19 patients with moderate to severe disease who survived acute illness were included in this prospective and partially retrospective study. Clinical assessment, laboratory tests, high-resolution computed tomography scans, and pulmonary function tests (PFTs) were performed at baseline, followed by radiological and lung function assessments at 6 and 24 months. RESULTS: Among 106 enrolled participants (mean age 62 ± 13.5 years; males: 61), 44 (41.5%) and 27 (25.4%) underwent radiological assessment at 6 and 24 months, respectively. Overall, 22.6% (24) of patients had residual radiological abnormalities. Overt fibrosis was observed in 12.2% of patients. Computed tomography disease severity and extent diminished significantly at 6 (13 ± 6, P < 0.001) and 24 months (11 ± 6, P < 0.001) from baseline. PFTs were performed in 65 (61.3%), 22 (20.7%), and 34 (32%) patients at baseline, 6 and 24 months, respectively. Impaired diffusion capacity (median diffusion capacity for carbon monoxide: 60%, interquartile range [IQR]: 51–80), restrictive lung defect (mean total lung capacity: 73.4% ± 18% predicted), and reduced exercise tolerance (median 6-min walk distance: 360 m, IQR: 210–400) were the predominant features at baseline. With the exception of exercise tolerance, a statistically significant improvement was observed in lung function parameters at the extended follow-up (2 years). CONCLUSIONS: Hospitalized COVID-19 survivors are at increased risk of developing long-term pulmonary complications, including lung fibrosis. A protocol-based approach to the management of post-COVID-19 patients is mandatory to improve future outcomes.