Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study: a prospective, multicentre, observational cohort study

Introduction
The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We sought to evaluate the excess burden of multiorgan abnormalities post-COVID-19 hospitalisation, evaluate their determinants and explore associations with patient-related outcome measures.

Methods
In a prospective UK-wide multicentre magnetic resonance imaging (MRI) follow-up study, 259 adults (aged ≥18 years) discharged from hospital following COVID-19 and 52 contemporary controls (no prior COVID-19, SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver and kidneys) which were both qualitatively (with clinical adjudication where relevant) and quantitatively assessed. Participants also underwent detailed recording of symptoms, physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls and this was further adjusted for potential confounders.

Findings
Patients discharged from hospital (March 2020 to November 2021) were assessed at a median of 5·0 months (IQR 4·3–6·4). Patients were older, living with more obesity, and had more comorbidities than non-COVID-19 controls. Multiorgan abnormalities were more frequent among patients versus controls (60·6% versus 26·9%, p<0·001) and independently associated with COVID-19 status (Odds Ratio 2·9 [95% CI 1·5, 5·8], p=0·002) after adjusting for relevant confounders. Patients were more likely to have lung abnormalities (p<0·001, parenchymal abnormalities), brain abnormalities (p<0·001, more white matter hyperintensities and regional brain volume reduction) and kidney abnormalities (p=0·014, lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were comparable between patients and controls. Abnormal MRI findings were more common in older patients with comorbidities and more severe acute infection, but also present in those with fewer comorbidities and less severe infection. Presence of lung MRI abnormalities was associated with a two-fold risk of chest tightness, whereas multiorgan abnormalities were associated with impaired patterns of patient-reported recovery.

Interpretation
Post-hospitalisation COVID-19 patients are at risk of multiorgan abnormalities in the medium term. Our findings emphasize the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.