The prognostic value of biomarker levels and chest imaging in patients with COVID-19 presenting to the emergency department

Introduction: We aimed to compare the prognostic value of a quantitative CT severity score with several laboratory parameters, particularly C-reactive protein, Procalcitonin, Neutrophil to lymphocyte ratio, D-dimer, ferritin, lactate dehydrogenase, lactate, troponin and B-type Natriuretic Peptide in predicting in-hospital mortality.

Methods: This was a retrospective chart review study of COVID-19 patients who presented to the Emergency Department of a tertiary care center between February and December 2020. All patients ≥18 years old who tested positive for the COVID-19 real-time reverse transcriptase polymerase chain reaction and underwent CT imaging at presentation were included. The primary outcome was the prognostic ability of CT severity score versus biomarkers in predicting in-hospital mortality.

Results: The AUCs were: D-dimer (AUC: 0.67 95% CI = 0.57-0.77), CT severity score (0.66, 95% CI = 0.55-0.77), LDH (0.66, 95% CI = 0.55-0.77), Pro-BNP (0.65, 95% CI = 0.55-0.76), NLR (0.64, 95% CI = 0.53-0.75) and troponin (0.64, 95% CI = 0.52-0.75). In the stepwise logistic regression, age (OR = 1.07 95% CI = 1.05-1.09), obesity (OR = 2.02 95% CI = 1.25-3.26), neutrophil/lymphocyte ratio (OR = 1.02 95% CI = 1.01-1.04), CRP (OR = 1.01 95% CI = 1.004-1.01), lactate dehydrogenase (OR = 1.003 95% CI = 1.001-1.004) and CT severity score (OR = 1.17 95% CI = 1.12-1.23) were significantly associated with in-hospital mortality.

Conclusion: In summary, CT severity score outperformed several biomarkers as a prognostic tool for covid related mortality. In COVID-19 patients requiring lung imaging, such as patients requiring ICU admission, patients with abnormal vital signs and those requiring mechanical ventilation, the results suggest obtaining and calculating the CT severity score to use it as a prognostic tool. If a CT was not performed, the results suggest using LDH, CRP or NLR if already done as prognostic tools in COVID-19 as these biomarkers were also found to be prognostic in COVID-19 patients.