Radio-Morphological Signs and Clinical Severity of Sars-Cov-2 Lineage B.1.1.7

Background: We aimed to assess the differences in the severity and chest-computed tomography (CT) radio-morphological signs of SARS-CoV-2 B.1.1.7 and non-B.1.1.7 variants. Methods: In this retrospective study, we collected clinical data of consecutive patients with laboratory-confirmed COVID-19 and chest-CT imaging who were admitted to the Emergency Department between 1st September – 13th November 2020 (non-B.1.1.7 cases) and 1st March – 18th March 2021 (B.1.1.7 cases). In addition to comparing demographic and clinical data, we also examined the differences in the severity and radio-morphological features associated with COVID-19 pneumonia. Total pneumonia burden (%), mean attenuation of ground-glass opacities (GGO) and consolidation were quantified using deep learning research software. Findings: The final population comprised 500 B.1.1.7 and 500 non-B.1.1.7 cases. The patients with B.1.1.7 infection were younger (58·5±15·6 vs 64·8±17·3; p<0·001) and had less comorbidities. Total pneumonia burden was higher in the B.1.1.7 patient group (16·1% [IQR:6·0-34·2%] vs 6·6% [IQR:1·2-18·3%]; p<0·001). In the age-specific analysis, in patients <60 years B.1.1.7 pneumonia had increased consolidation burden (0·1% [IQR:0·0-0·7%] vs 0·1% [IQR:0·0-0·2%]; p<0·001), and severe COVID-19 was more prevalent (11·5% vs 4·9%; p=0·032). Mortality rate was similar in all age groups. Furthermore, B.1.1.7 lineage was an independent predictor of pneumonia burden only in patients <60 years (s:15·0% (95%CI:6·7-23·4%); p<0·001). Interpretation: Despite B.1.1.7 patients were younger and had fewer comorbidities, they experienced more severe disease than non-B.1.1.7 patients, however the risk of death was the same between the two lineages. Clinical Trial Registration Details: Funding Information: NIH; National Research, Development and Innovation Fund of Hungary; Ministry for Innovation and Technology in Hungary. Declaration of Interests: None. Ethics Approval Statement: The clinical trial protocol was approved by the Ethics Committee of our University (SE RKEB: 256/2020).