Residual pulmonary infiltrates, symptoms and diffusion impairment at 1-year after severe COVID-19 infection have different associated factors

Abstract

Introduction: After severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia, patients may show lung sequelae on radiology and functional impairment at the 1-year follow-up. We aimed to describe the persistence of symptoms, radiological alterations, or reduced diffusing capacity of the lung for carbon monoxide (D_LCO ) at 1-year follow-up in patients from the Spanish Registry RECOVID.

Methods: RECOVID collected symptom and radiological and functional lung tests data on hospitalized patients with coronavirus disease 2019 during the acute phase and at the 6- and 12-month follow-up visits.

Results: Of the 2500 enrolled survivors (90% admitted to the ward), 1874 had follow-up visits for up to a year. Of these, 42% continued to present with symptoms, 27% had radiological sequelae and 31% had reduced D_LCO . Independently associated factors included female sex, asthma and the requirement for invasive or non-invasive mechanical ventilation. Complete radiological resolution was 72.2% at 12 months; associated factors with incomplete recovery were age, male sex, oxygen or respiratory support, corticosteroids and an initial SpO₂ /FiO₂ <450 or CURB-65 ≥2. Reduced D_LCO was observed in 31% of patients at 12 months; associated factors were older age, female sex, smoking habit, SpO₂ /FiO₂ <450 and CURB-65 ≥2 and the requirement of respiratory support.At 12 months, a proportion of the asymptomatic patients showed reduced D_LCO (9.5%), radiological findings (25%) or both (11%).

Conclusions: The factors associated with symptom persistence, incomplete radiological resolution and D_LCO <80% differed according to age, sex, comorbidities and respiratory support. The burden of symptoms, reduced D_LCO and incomplete radiological resolution were considerable in patients with SARS-CoV-2 pneumonia at the 1-year follow-up after hospitalisation.

Keywords: COVID-19; RECOVID; SARS-CoV-2; SEPAR.