Are mild or moderate COVID-19 patients at higher risk of VTE? A comparison of two prospective european cohorts inemergency departments

Background : Severely ill patients with SARS-CoV-2 have at increased risk of venous thromboembolism (VTE). However, the VTE risk in patients with mild to moderate COVID-19 remains uncertain. Aims : To assess the risk of VTE in patients with mild to moderate COVID-19 patients versus similar patients without COVID-19 and to define VTE risk factors in COVID-19 patients. Methods : A prospective cohort of patients presented to ED for acute dyspnea or chest pain and having confirmed or probable mild to moderate COVID-19 was retrospectively compared to a prospective cohort of similar ED patients using propensity score matching. Patients having diagnostic testing for suspected PE and for whom PE was initially ruled-out were included. Univariate and multivariate analysis of possible VTE risk factors were performed in the COVID-19 patients. The main outcome was the rate of symptomatic VTE, deep venous thrombosis or pulmonary embolism, within the 28 days after ED presentation. Results : A total of 2292 patients were included in the COVID-19 cohort and 1539 in the comparison cohort. After adjustment, the 28-day rate of symptomatic VTE was 1.87% (95%CI: 0.95 to 3.24) in the COVID-19 cohort and 0.18% (95%CI: 0.01 to 1.63) in the comparison cohort. The absolute difference was +1.69% (95%CI: 0.88 to 2.51, P 65 years were independent risk factors of symptomatic VTE but not the lack of thromboprophylaxis. Conclusions : Patients with mild-to-moderate COVID-19 presenting to ED had a higher risk of subsequent VTE than similar patients, especially if they are older than 65 years and required hospitalization.