Risk of recurrence after discontinuing anticoagulation in patients with COVID-19- associated venous thromboembolism: a prospective multicentre cohort study.

ABSTRACT

Background: The clinical relevance of recurrent venous thromboembolism (VTE) after discontinuing anticoagulation in patients with COVID-19-associated VTE remains uncertain. We estimated the incidence rates and mortality of VTE recurrences developing after discontinuing anticoagulation in patients with COVID-19-associated VTE. Methods: A prospective, multicenter, non-interventional study was conducted between March 25, 2020, and July 26, 2023, including patients who had discontinued anticoagulation after at least 3 months of therapy. All patients from the registry were analyzed during the study period to verify inclusion criteria. Patients with superficial vein thrombosis, those who did not receive at least 3 months of anticoagulant therapy, and those who were followed for less than 15 days after discontinuing anticoagulation were excluded. Outcomes were 1) Incidence rates of symptomatic VTE recurrences, and 2) fatal PE. The rate of VTE recurrences was defined as the number of patients with recurrent VTE divided by the patient-years at risk of recurrent VTE during the period when anticoagulation was discontinued. Findings: Among 1106 patients with COVID-19-associated VTE (age 62.3 ± 14.4 years; 62.9% male) followed-up for 12.5 months (p25-75, 6.3-20.1) after discontinuing anticoagulation, there were 38 VTE recurrences (3.5%, 95% confidence interval [CI] 2.5-4.7%), with a rate of 3.1 per 100 patient-years (95% CI 2.2-4.2). No patient died of recurrent PE (0%, 95% CI 0-7.6%). Subgroup analyses showed that patients with diagnosis in 2021-2022 (vs. 2020) (Hazard ratio [HR] 2.86; 95% CI 1.45-5.68) or those with isolated deep vein thrombosis (vs. pulmonary embolism) (HR 2.31; 95% CI 1.19-4.49) had significantly higher rates of VTE recurrences. Interpretation: In patients with COVID-19-associated VTE who discontinued anticoagulation after at least 3 months of treatment, the incidence rate of recurrent VTE and the case-fatality rate was low. Therefore, it conceivable that long-term anticoagulation may not be required for many patients with COVID-19-associated VTE, although further research is needed to confirm these findings. Funding: Sanofi and Rovi, Sanofi Spain.