Long-term respiratory consequences of COVID-19 related pneumonia: a cohort study

Background Our aims were to describe respiratory sequelae up to 12 months after discharge in COVID-19 patients with severe pneumonia requiring non-invasive respiratory support therapies. Methods This study was undertaken at University Hospital Doctor Josep Trueta (Girona, Spain) between March 2020 and June 2020. Three months after discharge, we evaluated their dyspnoea and performed Saint George's respiratory questionnaire, pulmonary function tests, blood test, 6-min walking test, and a high-resolution CT (HRCT). At the six and 12-month follow-up, we repeated all tests except for pulmonary function, 6-min walking test, and HRCT, which were performed only if abnormal findings had been previously detected. Results Out of the 94 patients recruited, 73% were male, the median age was 62.9 years old, and most were non-smokers (58%). When comparing data three and 12 months after discharge, the percentage of patients presenting dyspnoea [greater than or equal to] 2 decreased (19% vs 7%), the quality-of-life total score improved (22.8% vs 18.9%; p = 0.019), there were less abnormal results in the pulmonary function tests (47% vs 23%), the 6-min walking test distance was enhanced (368.3 m vs 390.7 m, p = 0.020), ground glass opacities findings waned (51.6% vs 11.5%), and traction bronchiectasis increased (5.6% vs 15.9%). Only age showed significant differences between patients with and without pulmonary fibrotic-like changes. Conclusion Most patients improved their clinical condition, pulmonary function, exercise capacity and quality of life one year after discharge. Nonetheless, pulmonary fibrotic-like changes were observed during the follow-ups. Keywords: COVID-19, Coronavirus disease, Long-term sequelae, Pneumonia, Pulmonary fibrosis