Pulmonary function and tomographic features in adult survivors of severe COVID-19 pneumonia: a prospective study of 12-month follow-up.

Abstract

<b>Introduction:</b> There is a lack of data on long-term sequelae of severe COVID-19 pneumonia beyond clinical follow-up at 6 months. <b>Aim:</b> To describe&nbsp;the evolution of pulmonary sequelae at 3, 6 and 12 months in severe COVID-19 survivors in terms of pulmonary function and high-resolution computed tomography (HRCT) of the chest. <b>Methods:</b> 84 subjects (74% male, median age: 63 [49-70]) hospitalized for COVID-19 pneumonia (January 2021-January 2022) were evaluated at 3, 6 and 12 months after discharge with spirometry, lung diffusing capacity (DLCO), 6-minute walking test (6MWT) and HRCT. <b>Results:</b> At 3, 6 and 12 months, 64%, 70% and 80% of patients were found to have normal spirometry (FVC: 83±6%, 96±2%, 97±2%]); DLCO &lt;80% was found in 66% (mean 77±1%), 63% (mean 74±2%) and 43% (mean 81±1%) of subjects; 6MWT performance was normal in 70% (median 494 m [582-472]), 84% (median 552 m [487-583]) and 100% (median 557 m [496-588]) of subjects. However, after 1 year of discharge, 50% of patients had persistent oxygen desaturation at the end of the 6MWT. HRCT abnormalities were detected at 3, 6 and 12 months in 87%, 60% and 43% of patients. The most prevalent HRCT patterns at 12 months were ground-glass opacities (71%), subpleural reticulation and atelectasis (35%) and bronchiectasis (10%). <b>Conclusions:</b> A high prevalence of persistent lung function and HRCT abnormalities was found in survivors of severe COVID-19 pneumonia. Evaluation at 3, 6 and 12 months showed progressively improving values of spirometry, DLCO and 6MWT over time. However, long-term HRCT anomalies and exercise-induced desaturation suggest persistent interstitial phenomena of unknown implications.