Evaluation of the occurrence of venous thromboembolic events in COVID-19 outpatients

INTRODUCTION: Thrombotic events are present at higher rates among COVID-19 patients. Prophylactic use of parenteral anticoagulants during hospitalisation is recommended to reduce the risk of complications. In this context, the Tunisian Anticoagulation Survey in COVID-19 patient General Practice experience (TASC-GP) was conducted. OBJECTIVE: The evaluation of the incidence of venous thromboembolic events (VTE) and bleedings in COVID-19 patients treated in ambulatory. METHOD: The TASC-GP is an observational, multicenter study included 3,383 patients from July to October 2021. The following up of patients was done 35 days after inclusion date with investigation of VTE and bleeding events. The four main enrolment criteria were: 1) age ≥ 18 years; 2) confirmed COVID-19 infection; 3) treated as an outpatient; 4) initiation of Rivaroxaban 10 mg/d. Patients were excluded if any of the following criteria applied: 1) the use of anticoagulant or thrombolytic drugs other than Rivaroxaban on admission or within days of admission; 2) the use of any dosage other than that specified in the study protocol. RESULTS: The mean age of the population was 51.6 ± 15.5 years with a sex ratio of 0.67, 30.7% of the population had hypertension, 23.4% were diabetic and 34.9% were obese. At least one cardiovascular comorbidity was observed in 40% of cases and 9.5% had chronic respiratory disease. The mean IMPROVE and IMPROVE DDimer scores were 0.65 ± 0.9 and 1.4 ± 1.4, respectively. The mean Improve bleeding score was 1.4 ± 1.5. A VTE was reported during follow-up in 39 patients (1.15%). Diabetes and chronic respiratory disease were independent factors for the occurrence of VTE with an odd ratio of 2.2 [95% CI 1.1–4.2] (P = 0.017) and 3.2 [95% CI 1.5–6.4] (P = 0.002) respectively. IMPROVE and IMPROVE DDimer scores were comparable in patients with and without VTE. There was no statistically significant increase in the rate of major bleeding (0.001%). The IMPROVE Bleeding score was comparable in the bleeding and non-bleeding groups at follow-up. There were no predictive factors for bleeding. CONCLUSION: Our study is in agreement with the literature concerning a decrease in the rate of thrombembolic complications when using prophylactic anticoagulation versus placebo. Other VTE estimation scores including chronic respiratory disease and diabetes can be proposed. The use of Rivaroxaban in this population was not associated with increased bleeding.