Assessment of chest CT abnormalities and pulmonary function at 6-month and 1-year after hospital discharge in Chinese patients of COVID-19 pneumonia at the turn of 2022–2023

TL;DR

This study tracked lung CT scans and function in Chinese patients recovering from COVID-19 pneumonia over one year, finding that lung abnormalities decreased but fibrosis increased and affected lung function.

Contribution

The study provides longitudinal data on CT abnormalities and pulmonary function in post-COVID-19 patients during the 2022–2023 China epidemic.

Findings

Pulmonary abnormalities decreased from 100% to 37.8% over one year, while fibrotic changes increased.

Fibrotic changes were strongly correlated with reduced diffusion capacity of the lung for carbon monoxide (DLCO).

DLCO was significantly lower in patients with fibrotic changes compared to those without.

Abstract

This study aimed to assess chest CT abnormalities and pulmonary function at 6-month and 1-year follow-ups in coronavirus disease 2019 (COVID-19) pneumonia patients of the China epidemic in the turn of 2022–2023.

A total of 156 hospitalized patients with COVID-19 pneumonia admitted between 29 November 2022 and 10 February 2023 were prospectively assessed at 6-month and 1-year follow-ups. Characteristics and CT scores of pulmonary abnormalities and pulmonary function were compared between different follow-up time points. The correlation of CT abnormalities and pulmonary function at 1-year were evaluated.

Over 1 year, the proportion of pulmonary abnormalities gradually decreased (initial, 100%, 156/156; 6-month, 57.1%, 89/156; and 1-year, 37.8%, 59/156; P < 0.001), whereas fibrotic changes increased (initial, 6.4%, 10/156; 6-month, 14.1%, 22/156; and 1-year, 14.7%, 23/56; P < 0.001). Compared to participants of the subgroup with nonfibrotic changes, diffusion capacity of the lung for carbon monoxide (DLCO)(P = 0.01) and DLCO less than 80% predicted (P < 0.001) showed significantly decrease in participants of the subgroup with fibrotic changes. The extent of fibrotic changes was strongly correlated with lower DLCO (r = −0.734, P < 0.001).

Fibrotic changes might show a tendency to persist over time and correlate strongly with impairment of diffusion function, thus requiring more attention in future follow-ups.

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