Mid-term pulmonary sequelae after hospitalisation for COVID-19: The French SISCOVID cohort

Abstract

Background: Even though COVID-19 clinical features, pathogenesis, complications, and therapeutic options have been largely described in the literature, long-term consequences in patients remain poorly known.

Methods: The French, multicentre, non-interventional SISCOVID study evaluated lung impairment three (M3) and six months (M6) after hospital discharge in patients recovered from COVID-19. Evaluation was based on clinical examination, pulmonary function tests, and chest computed tomography (CT-scan).

Results: Of the 320 included patients (mean age: 61 years; men: 64.1%), 205 had had a severe form of COVID-19, being hospitalised in an intensive care unit (ICU), and requiring high flow nasal cannula, non-invasive ventilation, or invasive mechanical ventilation. At M6, 54.1% of included patients had persistent dyspnoea (mMRC score ≥1), 20.1% severe impairment in gas diffusing capacity (DL_CO <60% pred.), 21.6% restrictive ventilatory pattern (total lung capacity <80% pred.), and 40% a fibrotic-like pattern at CT-scan. Fibrotic-like pattern and restrictive ventilatory pattern were significantly more frequent in patients recovered from severe than non-severe COVID-19. Improved functional and radiological outcomes were observed between M3 and M6. At M6, age was an independent risk factor for severe DLco impairment and fibrotic-like pattern and severe COVID-19 form was independent risk factor for restrictive ventilatory profile and fibrotic-like pattern.

Conclusion: Six months after discharge, patients hospitalised for COVID-19, especially those recovered from a severe form of COVID-19, frequently presented persistent dyspnoea, lung function impairment, and persistent fibrotic-like pattern, confirming the need for long-term post-discharge follow-up in these patients and for further studies to better understand long-term COVID-19 lung impairment.

Keywords: COVID-19; observational study; patient discharge; pneumonia; sequelae.

Fig. 1

Flowchart of the study. CT: computed tomography.

Fig. 2

Comparison of most relevant pathological findings between 3-month and 6-month follow-up visits after COVID-19. Proportion computed on the whole population, including missing values. 6MWT: six-minute walk test; CT: computed tomography; DL_CO: diffusing capacity of the lung for carbon monoxide; mMRC: modified Medical Research Council dyspnoea scale; NA: not available; PaO2: partial pressure of oxygen; TLC: total lung capacity.