Relation of Pulmonary Diffusing Capacity Decline to HRCT and VQ SPECT/CT Findings at Early Follow-Up after COVID-19: A Prospective Cohort Study (The SECURe Study)

Abstract

A large proportion of patients exhibit persistently reduced pulmonary diffusion capacity after COVID-19. It is unknown whether this is due to a post-COVID restrictive lung disease and/or pulmonary vascular disease. The aim of the current study was to investigate the association between initial COVID-19 severity and haemoglobin-corrected diffusion capacity to carbon monoxide (DLco) reduction at follow-up. Furthermore, to analyse if DLco reduction could be linked to pulmonary fibrosis (PF) and/or thromboembolic disease within the first months after the illness, a total of 67 patients diagnosed with COVID-19 from March to December 2020 were included across three severity groups: 12 not admitted to hospital (Group I), 40 admitted to hospital without intensive care unit (ICU) admission (Group II), and 15 admitted to hospital with ICU admission (Group III). At first follow-up, 5 months post SARS-CoV-2 positive testing/4 months after discharge, lung function testing, including DLco, high-resolution CT chest scan (HRCT) and ventilation-perfusion (VQ) single photon emission computed tomography (SPECT)/CT were conducted. DLco was reduced in 42% of the patients; the prevalence and extent depended on the clinical severity group and was typically observed as part of a restrictive pattern with reduced total lung capacity. Reduced DLco was associated with the extent of ground-glass opacification and signs of PF on HRCT, but not with mismatched perfusion defects on VQ SPECT/CT. The severity-dependent decline in DLco observed early after COVID-19 appears to be caused by restrictive and not pulmonary vascular disease.

Olfactory and Gustatory Outcomes Including Health-Related Quality of Life 3–6 and 12 Months after Severe-to-Critical COVID-19: A SECURe Prospective Cohort Study

“…We included 29 consecutive patients from March to May 2020 at Rigshospitalet, Copenhagen University Hospital, Denmark. The patients were a subgroup of the prospective SECURe cohort (Sequelae COVID-19, University Hospital, Rigshospitalet) [ 28 ]. The SECURe cohort included those patients with severe-to-critical COVID-19 in need of hospitalisation and, in some cases, admittance to the intensive care unit (ICU) and mechanical ventilation.…”

Cardiorespiratory dysautonomia in post‐COVID‐19 condition: Manifestations, mechanisms and management

“…Lung function impairment with low total lung capacity, low forced vital capacity and lung diffusion impairment is common after severe COVID‐19 requiring hospitalization [37, 42]. Similarly, radiological findings have been found in a significant proportion of patients previously hospitalized [43–46]. Three months after confirmed COVID‐19‐related pneumonia, ground glass opacities were found in 75% of patients, reticulations in 30% and residual subpleural infiltration in 13% [47].…”

Pulmonary diffusing capacity for carbon monoxide and nitric oxide after COVID‐19: A prospective cohort study (the SECURe study)

“…Besides common pulmonary symptoms, such as breathlessness, chest pain and fatigue, grouped under the term 'long COVID' , numerous studies have reported a severity-dependent reduction in pulmonary diffusing capacity (D L ) (Huntley et al, 2022;Katzenstein et al, 2022;Watanabe et al, 2022).…”

“…After the initial surge of the coronavirus disease 2019 (COVID‐19) pandemic, it became evident that the pulmonary effects of the disease often lasted far beyond the immediate severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection (Crook et al., 2021 ). Besides common pulmonary symptoms, such as breathlessness, chest pain and fatigue, grouped under the term ‘long COVID’, numerous studies have reported a severity‐dependent reduction in pulmonary diffusing capacity ( D L ) (Huntley et al., 2022 ; Katzenstein et al., 2022 ; Watanabe et al., 2022 ).…”

“…Morphologically, the post‐COVID reduction in D L has been shown to be caused by a fibrosis‐like restrictive lung disease rather than pulmonary vascular disease (Katzenstein et al., 2022 ). These changes appear to be reversible, at least in part, although residual parenchymal damage is often observed in severe cases (Lee et al., 2022 ; Torres‐Castro et al., 2021 ; Zhao et al., 2020 ).…”