Incidence of symptomatic, image-confirmed venous thromboembolism following hospitalization for COVID-19 with 90-day follow-up

Abstract

Although COVID-19 has been reported to be associated with high rates of venous thromboembolism (VTE), the risk of VTE and bleeding after hospitalization for COVID-19 remains unclear, and the optimal hospital VTE prevention strategy is not known. We collected retrospective observational data on thrombosis and bleeding in 303 consecutive adult patients admitted to the hospital for at least 24 hours for COVID-19. Patients presenting with VTE on admission were excluded. Data were collected until 90 days after admission or known death by using medical records and an established national VTE network. Maximal level of care was ward based in 78% of patients, with 22% requiring higher dependency care (12% noninvasive ventilation, 10% invasive ventilation). Almost all patients (97.0%) received standard thromboprophylaxis or were already receiving therapeutic anticoagulation (17.5%). Symptomatic image-confirmed VTE occurred in 5.9% of patients during index hospitalization, and in 7.2% at 90 days after admission (23.9% in patients requiring higher dependency care); half the events were isolated segmental or subsegmental defects on lung imaging. Bleeding occurred in 13 patients (4.3%) during index hospitalization (1.3% had major bleeding). The majority of bleeds occurred in patients on the general ward, and 6 patients were receiving treatment-dose anticoagulation, highlighting the need for caution in intensifying standard thromboprophylaxis strategies. Of 152 patients discharged from the hospital without an indication for anticoagulation, 97% did not receive thromboprophylaxis after discharge, and 3% received 7 days of treatment with low molecular weight heparin after discharge. The rate of symptomatic VTE in this group at 42 days after discharge was 2.6%, highlighting the need for large prospective randomized controlled trials of extended thromboprophylaxis after discharge in COVID-19.

COVID-19-associated coagulopathy and antithrombotic agents—lessons after 1 year

“… 4 , 10 , 11 In non-hospitalised patients with COVID-19—ie, those with mild disease—the incidence of venous thromboembolism is unknown. A recent study 12 found a venous thromboembolism incidence of 2·6% in the first 90 days after hospital discharge in patients who did not use anticoagulant therapy or prophylaxis, but another study 13 found a much lower incidence of 4·8 per 1000 discharged patients, which was similar to the incidence shown in patients who were discharged after admission for non-COVID-19 related disease. In addition to venous thromboembolism, increased prevalence of arterial thrombotic events such as myocardial and cerebral infarction (up to 3%, 95% CI 2–5% in an ICU setting) has been reported, 14 and remarkably high numbers of thrombosis in extracorporeal circuits (up to 8%) have been observed.…”

Prevention of venous thromboembolism and haemostasis monitoring in patients with COVID-19: Updated proposals (April 2021)

“…Analysis from the first wave reported that COVID-19 ARDS patients developed more thrombotic complications compared to non-COVID-19 ARDS patients [9] . Intensive Care Unit (ICU) admission and the need for mechanical ventilation have been identified as independent risk factors for thrombosis in COVID-19 [10] . Thrombotic events are independently associated with mortality [11] .…”

Epidemiology and organ specific sequelae of post-acute COVID19: A narrative review

“…The cumulative incidence of thrombosis and hemorrhage at day 30 post discharge were reported to be 2.5% and 3.7% respectively in the USA (Appendix Table 2) [73]. Retrospective studies from the UK have shown a similar rate of venous thromboembolism of approximately 3%, whereas it has been estimated that the odds of such events following a hospital discharge are 60% higher in the post-acute COVID-19 setting compared to 2019 [101,102]. However, even lower rates of deep vein thrombosis (<1%) assessed by venous ultrasound have been reported in other prospective, post-acute COVID-19 studies conducted in Belgium and China, including a low proportion of patients receiving thromboprophylaxis [103,104].…”