Comparison of Blood Coagulation Function of Severe Patients Infected with SARS-CoV-2 Original Strain and Omicron Variant in China: A Single Center Retrospective Analysis

This study aims to analyze the characteristics of blood coagulation function in severe patients infected with Omicron variant in comparison to those infected with the original strain. Seventy-three severe patients infected with the Omicron variant and hospitalized at Wuhan First Hospital from 9 December 2022 to 9 January 2023, were included, as well as 71 severe patients infected with the original strain and hospitalized at the same institution from 12 February to 20 March 2020. Patients infected with Omicron demonstrated significant coagulation dysfunction, as evidenced by dramatically elevated levels of FIB, APTT, PT, INR, and D-D and decreased values of PLT compared to the healthy control group (P < 0.01). The patients infected with the Omicron variant exhibited more complex and worse coagulation disorders (dramatic elevation of FIB, APTT, PT, and D-D and decrease of PLT) than the patients infected with the original strain (P < 0.05). In addition, individuals infected with the Omicron variant experienced a decreased length of hospitalization but a higher mortality rate when compared to those infected with the original strain (P < 0.01). We found the FIB, D-D, LDH, and CRP values of non-survivors were much higher than those of survivors among patients infected with Omicron (P < 0.05). In general, patients with severe cases of Omicron infection consistently showed more pronounced coagulation dysfunction upon admission compared to those infected with the original strain, potentially due to their older age and higher prevalence of cardiovascular and cerebrovascular diseases. The study provides a realistic basis for clinical prevention and treatment of severe or critically ill cases of COVID-19 caused by the Omicron variant or new evolving variants in the future.