Scientific article
Open access

Pulmonary Recovery 12 Months after Non-Severe and Severe COVID-19: The Prospective Swiss COVID-19 Lung Study

Published inRespiration, vol. 102, no. 2, p. 120-133
First online date2022-12-23

Background: Lung function impairment persists in some patients for months after acute coronavirus disease 2019 (COVID-19). Long-term lung function, radiological features, and their association remain to be clarified.

Objectives: We aimed to prospectively investigate lung function and radiological abnormalities over 12 months after severe and non-severe COVID-19.

Methods: 584 patients were included in the Swiss COVID-19 lung study. We assessed lung function at 3, 6, and 12 months after acute COVID-19 and compared chest computed tomography (CT) imaging to lung functional abnormalities.

Results: At 12 months, diffusion capacity for carbon monoxide (DLCOcorr) was lower after severe COVID-19 compared to non-severe COVID-19 (74.9% vs. 85.2% predicted, p < 0.001). Similarly, minimal oxygen saturation on 6-min walk test and total lung capacity were lower after severe COVID-19 (89.6% vs. 92.2%, p = 0.004, respectively, 88.2% vs. 95.1% predicted, p = 0.011). The difference for forced vital capacity (91.6% vs. 96.3% predicted, p = 0.082) was not statistically significant. Between 3 and 12 months, lung function improved in both groups and differences in DLCO between non-severe and severe COVID-19 patients decreased. In patients with chest CT scans at 12 months, we observed a correlation between radiological abnormalities and reduced lung function. While the overall extent of radiological abnormalities diminished over time, the frequency of mosaic attenuation and curvilinear patterns increased.

Conclusions: In this prospective cohort study, patients who had severe COVID-19 had diminished lung function over the first year compared to those after non-severe COVID-19, albeit with a greater extent of recovery in the severe disease group.

  • COVID-19 sequelae
  • Long COVID
  • SARS-CoV-2
  • SARS-CoV-2 lung functional sequelae
  • SARS-CoV-2 radiological sequelae
  • Humans
  • Prospective Studies
  • Switzerland / epidemiology
  • COVID-19
  • Respiratory Insufficiency
  • Lung / diagnostic imaging
Citation (ISO format)
LENOIR, Alexandra et al. Pulmonary Recovery 12 Months after Non-Severe and Severe COVID-19: The Prospective Swiss COVID-19 Lung Study. In: Respiration, 2022, vol. 102, n° 2, p. 120–133. doi: 10.1159/000528611
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Article (Published version)
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ISSN of the journal0025-7931

Technical informations

Creation10/20/2023 1:32:02 PM
First validation11/14/2023 11:07:59 AM
Update time11/14/2023 11:07:59 AM
Status update11/14/2023 11:07:59 AM
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