Frequency of venous thromboembolism in 6513 patients with COVID-19: a retrospective study

Patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) appear to be at increased risk for venous thromboembolism (VTE), especially if they become critically ill with COVID-19. Some centers have reported very high rates of thrombosis despite anticoagulant prophylaxis. The electronic health record (EHR) of a New Orleans-based health system was searched for all patients with polymerase chain reaction-confirmed SARS-CoV-2 infection who were either admitted to hospital or treated and discharged from an emergency department between 1 March 2020 and 1 May 2020. From this cohort, patients with confirmed VTE (either during or after their hospital encounter) were identified by administrative query of the EHR.: Between 1 March 2020 and 1 May 2020, 6153 patients with COVID-19 were identified; 2748 of these patients were admitted, while 3405 received care exclusively through the emergency department. In total, 637 patients required mechanical ventilation and 206 required renal replacement therapy. Within the hospitalized cohort, the overall mortality rate was 24.5% and VTE occurred in 86 patients (3.1%). In the 637 patients who required mechanical ventilation at some point during their hospital stay, 45 developed VTE (7.2%). After a median follow-up of 14.6 days, VTE had been diagnosed in 3 of the 2075 admitted who were discharged alive (0.14%). Among 6153 patients with COVID-19 who were hospitalized or treated in emergency departments, we did not find evidence of unusually high VTE risk. Pending further evidence from prospective, controlled trials, our findings support a traditional approach to primary VTE prevention in patients with COVID-19.