A prospective study of pulmonary outcomes and chest computed tomography in the first year after COVID-19

Tøri Vigeland Lerum; Carin Meltzer; Jezabel Riverio Rodriguez; Trond Mogens Aaløkken; Eivind Brønstad; Bernt B Aarli; Kristine Marie Aarberg-Lund; Michael T Durheim; Haseem Ashraf; Gunnar Einvik; Ole Henning Skjønsberg; Knut Stavem

doi:10.1183/23120541.00575-2022

A prospective study of pulmonary outcomes and chest computed tomography in the first year after COVID-19

ERJ Open Res. 2023 Mar 13;9(2):00575-2022. doi: 10.1183/23120541.00575-2022. eCollection 2023 Mar.

Authors

Tøri Vigeland Lerum^{1

2}, Carin Meltzer³, Jezabel Riverio Rodriguez³, Trond Mogens Aaløkken^{2

3}, Eivind Brønstad^{4

5}, Bernt B Aarli^{6

7}, Kristine Marie Aarberg-Lund⁸, Michael T Durheim^{2

9}, Haseem Ashraf^{2

10}, Gunnar Einvik^{2

11}, Ole Henning Skjønsberg^{1

2}, Knut Stavem^{2

11

12}

Affiliations

¹ Department of Pulmonary Medicine, Oslo University Hospital, Oslo, Norway.
² Institute for Clinical Medicine, University of Oslo, Oslo, Norway.
³ Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
⁴ Thoracic Department, St Olav's Hospital, Trondheim, Norway.
⁵ Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, NTNU, Trondheim, Norway.
⁶ Department of Thoracic Medicine, Haukeland University Hospital, Bergen, Norway.
⁷ Department of Clinical Science, University of Bergen, Bergen, Norway.
⁸ Department of Infectious Diseases, Østfold Hospital Trust Kalnes, Grålum, Norway.
⁹ Department of Respiratory Medicine, Oslo University Hospital, Oslo, Norway.
¹⁰ Department of Diagnostic Imaging, Akershus University Hospital, Lørenskog, Norway.
¹¹ Pulmonary Department, Akershus University Hospital, Lørenskog, Norway.
¹² Health Services Research Unit, Akershus University Hospital, Lørenskog, Norway.

Abstract

COVID-19 primarily affects the respiratory system. We aimed to evaluate how pulmonary outcomes develop after COVID-19 by assessing participants from the first pandemic wave prospectively 3 and 12 months following hospital discharge. Pulmonary outcomes included self-reported dyspnoea assessed with the modified Medical Research Council dyspnoea scale, 6-min walk distance (6MWD), spirometry, diffusing capacity of the lung for carbon monoxide (D _LCO), body plethysmography and chest computed tomography (CT). Chest CT was repeated at 12 months in participants with pathological findings at 3 months. The World Health Organization (WHO) ordinal scale for clinical improvement defined disease severity in the acute phase. Of 262 included COVID-19 patients, 245 (94%) and 222 (90%) participants attended the 3- and 12-month follow-up, respectively. Self-reported dyspnoea and 6MWD remained unchanged between the two time points, while D _LCO and total lung capacity improved (0.28 mmol·min^-1·kPa^-1, 95% CI 0.12-0.44, and 0.13 L, 95% CI 0.02-0.24, respectively). The prevalence of fibrotic-like findings on chest CT at 3 and 12 months in those with follow-up chest CT was unaltered. Those with more severe disease had worse dyspnoea, D _LCO and total lung capacity values than those with mild disease. There was an overall positive development of pulmonary outcomes from 3 to 12 months after hospital discharge. The discrepancy between the unaltered prevalence of self-reported dyspnoea and the improvement in pulmonary function underscores the complexity of dyspnoea as a prominent factor of long-COVID. The lack of increase in fibrotic-like findings from 3 to 12 months suggests that SARS-CoV-2 does not induce a progressive fibrotic process in the lungs.