The Role of Pulmonary Function Testing and Lung Imaging in the Long-Term Follow-Up of Patients with COVID-19 Pneumonia Role of Pulmonary Function Tests and High-Resolution Computed Tomography in Post-COVID-19 Interstitial Lung Disease

Background: Post-COVID-19 Interstitial Lung Disease (PC-ILD) is characterized by fibrotic-like signs at high-resolution computed tomography (HRCT) and pulmonary function tests (PFTs) abnormalities after SARS-CoV-2 infection. It is still not clear how frequent these tests should be performed to rule out long-term consequences of COVID-19 pneumonia. Objectives: The aims of our study were to evaluate the incidence and risk factors of PC-ILD and possibly to propose a long-term follow-up program. Method: One-hundred patients, hospitalized in our ward for moderate to critical COVID-19, underwent two follow-up visits at three and 15 months in which PFTs and HRCT were performed. Results: At the 15-month follow-up, 8% of patients showed residual radiological and functional signs consistent with PC-ILD. All but one of these patients had already demonstrated PFTs and HRCT alterations at first follow-up visit, and the last 1 patient showed worsening of lung function during follow-up. These findings highlight the negative predictive value of PFTs at 3-month follow-up for the development of PC-ILD. Aging, severity of COVID-19, and degree of pulmonary involvement during acute infection proved to be significant risk factors for developing PC-ILD. Conclusions: Our study highlights the importance of PFTs in the long-term follow-up of patients affected by moderate to critical COVID-19 pneumonia. Further studies are needed to confirm our hypothesis that HRCT should be performed only in patients with PFTs abnormalities.

Automated summary

This study evaluated the incidence and risk factors of Post-COVID-19 Interstitial Lung Disease (PC-ILD) in 100 patients with moderate to critical COVID-19. It found that 8% of patients showed residual radiological and functional signs consistent with PC-ILD at the 15-month follow-up. Aging, severity of COVID-19, and degree of pulmonary involvement during acute infection were identified as significant risk factors for developing PC-ILD.