A Comparison of Clinical and Laboratory Manifestations of Thrombotic Events in Patients with COVID-19 and Other Respiratory Viral Infections

Background: COVID-19 caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and other respiratory viral (non-CoV-2-RV) infections are associated with thrombotic complications. The differences in prothrombotic potential between SARS-CoV-2 and non-CoV-2-RV have not been well characterised. We compared the thrombotic rates between these two groups of patients directly and further delved into their coagulation profiles. Methods: In this single-center, retrospective cohort study, all consecutive COVID-19 and non-CoV-2-RV patients admitted between January 15th and April 10th 2020 were included. Coagulation parameters studied were prothrombin time and activated partial thromboplastin time and its associated clot waveform analysis (CWA) parameter, min1, min2 and max2. Findings: In the COVID-19 (n=181) group there were two (1.0 event/1000-hospital-days) thrombotic events while one (1.8 event/1000-hospital-day) was reported in the non-CoV-2-RV (n=165) group. All of these events were myocardial infarction occurring in the intensive care unit. Coagulation parameters did not differ throughout the course of mild COVID-19. However, CWA parameters were significantly higher in severe COVID-19 compared with mild disease, suggesting hypercoagulability (min1: 6.48%/s vs 5.05%/s, P