After one year, 40% of COVID pneumonia patients still have lung problems

A recent study published in the journal Respiratory Research found lung dysfunction and shortness of breath among survivors of severe COVID-19 pneumonia one year after infection. Meanwhile, many COVID-19 patients have developed fibrotic-like sequelae as a result of mild or severe infection-associated pneumonia.

​​​​​​Stady: Lung function and radiological findings one year after COVID-19: a potential follow-up. Image Credit: People Image Studio / Shutterstock


First reported in Wuhan, China, at the end of 2019, the outbreak of Coronavirus 2 (SARS-CoV-2) spread globally to cause the coronavirus disease 2019 (COVID-19), which has claimed more lives. of 6.5 million people worldwide. The disease primarily affects the respiratory system with long-term sequelae often referred to as post-COVID syndrome or COVID protracted syndrome.

Prolonged COVID symptoms range from persistent headaches and muscle pain to permanent disabilities, affecting survivors’ quality of life. Approximately one third of affected patients develop acute respiratory distress syndrome (ARDS), while fibrous lung lesions develop in many.

Evidence suggests that patients undergoing mechanical ventilation during the acute phase of COVID-19 experience more pulmonary cell, endothelial, and alveolar cell changes, as well as interstitial and pulmonary fibrotic changes than those on conventional oxygen. A quarter of patients who developed pneumonia had cystic/retinal subpleural lesions, and a third of patients had fibrotic changes one year and six months after discharge, respectively.

the study

This prospective, prospective, multicenter, cohort study evaluated patients with bilateral pneumonia as a pulmonary consequence of SARS-CoV-2 infection – for lung function changes and persistent fibrotic lesions 1 year after hospital discharge.

The study was conducted in Spain and enrolled all adult patients discharged from respiratory services with a life expectancy of more than one year. Functional changes, development of dyspnea, and exercise capacity were assessed after discharge – at two months (V1), six months (V2), and twelve months (V3).


The average age of the participants was 60.5 years, and the majority were male. Notably, males showed a greater likelihood of more severe disease. In addition, length of hospital stay, laboratory parameters (C-reactive protein, lymphocyte count, lactate dehydrogenase, D-dimer, and ferritin levels), and RALE scores varied between study groups (Opposite V1, V2, V3). While there were no significant differences between study groups with regard to patient demographics, such as – body mass index (BMI), age, smoking, and comorbidities.

Intensity-time interaction plot based on a post hoc analysis of the mixed linear model. The squares indicate the average. Error bars show 95% confidence interval with Bonferroni correction. V1 (2 months), V2 (6 months), and V3 (12 months). group 1: light; Group 2: moderate, group 3: severe. a Reaction plot: changes over time and intensity in % of predicted DLCO. We found differences between sanity and temperance [p = 0.001] or severe [p < 0.001] Patients only 2 months old (V1). B Interaction chart: changes over time and intensity in the predicted forced vital capacity ratio. No between-group differences were found at any time. c Interaction chart: changes over time and severity of shortness of breath. No between-group differences were found at any time. Forced vital capacity FVC, DLCO The spread of the lungs’ capacity for carbon monoxide.​​​​​​

Pulmonary function tests revealed that 53.8% of patients had an impairment of diffusion after two months, which gradually improved after six months and one year. The mean lung diffusion capacity for carbon monoxide abnormalities (DLCO) was 78.5 in V1, 81.6 in V2, and 84 in V3. Significant changes in prevalence at 60 days—relative to time and severity—were found among moderate, moderate, and severe patients.

Across the group, a restricted abnormality was observed in 14.3% of patients at two months, 9.3% at six months, and 6.7% at 12 months. The mean forced vital capacity (FVC) was 99 in V1, 100.8 in V2, and 104.2 in V3. Meanwhile, no significant differences were found in forced vital capacity relative to time and severity.

Next, the cohort was analyzed for dyspnea. The mMRC scale depicts dyspnea ≥2 in 21.5% of patients in V1, 11.3% in V2, and 9.8% in V3. A significant association was found between dyspnea and follow-up time. However, significant time-dependent differences between severity groups were absent.

In addition, fixed lung volumes remained comparable between groups, while the six-minute walk test (6MWT) showed differences in the distance traveled by pedestrians—and intensity was the confounding factor. Variable DLCO (<80% at 12 months) is associated with age, female sex, ferritin levels and body mass index.

Computed tomography (CT) was advised 2 months after discharge in patients with abnormal chest x-rays, abnormal lung function test results, and persistent dyspnea. HRCT was performed 2 months later on 325 patients. Of these, 38.4% revealed complete resolution, while the rest showed ground glass opacity (GGO). Notably, GGO was the most common (at 73.5%) and showed differences based on age groups.

CT scans were repeated in patients with previous abnormal CT findings 1 year after discharge. Overall, 156 out of 200 patients had CT scans in V3 – 78.8% of them showed persistent radiological changes. Among the 200 patients, 45.5% had GGO; The reticular pattern is found in 34% of patients. Parenchymal bands were found in 33.4%, and traction bronchiectasis were seen in 30.8%.

Of the 156 patients, 102 patients revealed fibrotic-like sequelae, depicted by CT scan performed at 12 months. Significant changes between age groups were frequently detected in severe cases.

Lactate dehydrogenase (LDH) and lung involvement, as seen on radiographs during admission, were associated with the fibrotic pattern in V3.


Several patients with SARS-CoV-2-associated pneumonia developed fibrotic sequelae and showed shortness of breath and impaired lung function one year after hospital discharge. Therefore, further follow-up of patients who experienced severe COVID-19-associated pneumonia to study the development of fibrotic lesions over time is warranted.