Parenchymal involvement on CT pulmonary angiography in SARS-CoV-2 Alpha variant infection and correlation of COVID-19 CT severity score with clinical disease severity and short-term prognosis in a UK cohort

Abstract

To determine if there is a difference in radiological, biochemical, or clinical severity between patients infected with Alpha-variant SARS-CoV-2 compared with those infected with pre-existing strains, and to determine if the computed tomography (CT) severity score (CTSS) for COVID-19 pneumonitis correlates with clinical severity and can prognosticate outcomes.MATERIALS AND METHODS: Blinded CTSS scoring was applied to 137 hospital patients who had undergone both CT pulmonary angiography (CTPA) and whole-genome sequencing of SARS-CoV-2 within 14 days of CTPA between 1/12/20e5/1/21.RESULTS: There was no evidence of a difference in imaging severity on CTPA, viral load, clinical parameters of severity, or outcomes between Alpha and preceding variants. CTSS on CTPA strongly correlates with clinical and biochemical severity at the time of CTPA, and with patient outcomes. Classifying CTSS into a binary value of "high" and "low", with a cut-off score of 14, patients with a high score have a significantly increased risk of deterioration, as defined by subsequent admission to critical care or death (multivariate hazard ratio [HR] 2.76, p<0.001), and hospital length of stay (17.4 versus 7.9 days, p<0.0001).CONCLUSION: There was no evidence of a difference in radiological severity of Alpha variant infection compared with pre-existing strains. High CTSS applied to CTPA is associated with increased risk of COVID-19 severity and poorer clinical outcomes and may be of use

Comparison of CT findings of coronavirus disease 2019 (COVID-19) pneumonia caused by different major variants

“…In contrast, there was no significant radiological difference between wild type and Alpha variant. This was also consistent with a previous report from the UK that compared the chest CT findings of these subtypes [ 8 ].…”

“…In contrast, there was no significant radiological difference between wild type and Alpha variant. This was Data are shown as absolute numbers (percentage), mean ± standard deviation GGO Ground-glass opacity, w a One-way analysis of variance b Pearson χ 2 test or Fisher's exact test c Bonferroni corrected p = 0.06 for wild type vs. Alpha variant, Bonferroni corrected p = 0.1 for wild type vs. Delta variant, and Bonferroni corrected p = 1.0 for Alpha variant vs. Delta variant d Bonferroni corrected p = 1.0 for wild type vs. Alpha variant, Bonferroni corrected p = 0.012 for wild type vs. Delta variant, and Bonferroni corrected p = 0.003 for Alpha variant vs. Delta variant e Bonferroni corrected p = 0.8 for wild type vs. Alpha variant, Bonferroni corrected p = 0.3 for wild type vs. Delta variant, and Bonferroni corrected p = 0.033 for Alpha variant vs. Delta variant f Bonferroni corrected p = 1.0 for wild type vs. Alpha variant, Bonferroni corrected p = 0.003 for wild type vs. Delta variant, and Bonferroni corrected p < 0.001 for Alpha variant vs. also consistent with a previous report from the UK that compared the chest CT findings of these subtypes [8]. This study is subject to limitations and challenges.…”

“…Chest CT severity scores of each subtype were summarized in Table 6. Median (with [interquartile range]) total chest CT scores of wild type, Alpha variant, and Delta variant were as follows: 2 [0-4], 1 [0-3.75], 6.5 [3][4][5][6][7][8] on days 1-4 (all, p = 0.008.; wild type vs. Alpha variant, Bonferroni corrected p = 1.0; wild type vs. Delta variant, Bonferroni Representative CT images of each subtype were shown in Fig. 2.…”

“…To date, two studies have investigated the radiological differences between the variant types of COVID-19. One from the UK detected no difference in the CT severity score between patients infected with Alpha variant and wild type [ 8 ] The other one from China revealed the chest CT findings of children infected with Delta variant to be milder and to improve more quickly as compared to the wild type [ 9 ]. However, the CT findings of variant types of COVID-19 have yet to be sufficiently investigated especially in adult Asian populations.…”

Reduction in Chest CT Severity and Improved Hospital Outcomes in SARS-CoV-2 Omicron Compared with Delta Variant Infection

“…Multiple studies have shown the degree of parenchymal involvement on CT imaging to associate with disease severity and poor hospital outcomes, including a study that used a 25-point chest CT severity score (CT-SS) of CT pulmonary angiograms 6 . Further studies have evaluated the CT imaging characteristics or ‘signature’ of SARS-COV-2 infection 7 , 8 , but studies evaluating the lung imaging findings of Omicron infection versus non-Omicron variants remain lacking.…”