OC 52.4 - Venous Thromboembolism after Hospitalization for COVID-19: The Venous Thrombosis Virtual Surveillance in COVID-19 (VVIRTUOSO) Prospective Cohort Study

Tuesday, June 25, 2024

10:15 – 10:30 ICT

Room: Ballroom B2

Presenting Author(s)

Deborah Siegal, MD MSc FRCPC

Associate Professor
University of Ottawa and Ottawa Hospital Research Institute
Ottawa, Ontario, Canada

Co-Author(s)

MA

Marie-Pier Arsenault

Assistant Professor
University of Montreal
Montreal, Quebec, Canada
JA

Jameel Abdulrehman

Assistant Professor
University of Toronto
Toronto, Ontario, Canada
AC

Andrea Cervi

Adjunct Clinical Associate Professor
University of Windsor
Windsor, Ontario, Canada
AC

Andrew Cheung

Assistant Professor
McMaster University
Hamilton, Ontario, Canada
Adam Cuker, MD, MS

Department of Medicine and Department of Pathology and Laboratory Medicine
Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
Philadelphia, Pennsylvania, United States
MK

Maral Koolian

Assistant Professor
McGill University
Montreal, Quebec, Canada
Gregoire Le Gal

Hematologist
University of Ottawa
Ottawa, Ontario, Canada
RM

Ranjeeta Mallick

Statistician
Ottawa Hospital Research Institute
Ottawa, Ontario, Canada
CR

Chantal Rockwell

Research Coordinator
Ottawa Hospital Research Institute
Ottawa, Ontario, Canada
PS

Prism Schneider

Associate Professor
University of Calgary
Calgary, Alberta, Canada
RZ

Ryan Zarychanski

Associate Professor
University of Manitoba
Winnipeg, Manitoba, Canada
Marc Carrier, MD

Professor
Department of Medicine, University of Ottawa at the The Ottawa Hospital
Ottawa, Ontario, Canada

Background: COVID-19 induces a prothrombotic state that increases the risk of venous thromboembolism (VTE) in hospitalized patients, but the incidence of post-discharge VTE is not well characterized in prospective studies.

Aims: To determine the incidence of symptomatic VTE (deep vein thrombosis [DVT] and pulmonary embolism [PE]) after hospital discharge in patients with COVID-19.

Methods: VVIRTUOSO was a prospective multi-centre cohort study in Canada. Patients ≥18 years, hospitalized for COVID-19 or diagnosed during hospitalization, and discharged within prior 7 days were included. Patients with unconfirmed COVID-19, therapeutic anticoagulation, inability to provide informed consent or complete virtual assessments were excluded. The primary outcome was symptomatic objectively confirmed acute VTE (DVT and/or PE) at 90 days. Secondary outcomes included 30-day incidence of symptomatic VTE, major bleeding, clinically relevant non-major bleeding (CRNMB), mortality, and re-hospitalization or emergency department visit. VTE and bleeding events were adjudicated. Baseline characteristics were summarized using mean (standard deviation [SD]) and percentage, as appropriate. We calculated the cumulative incidence of primary and secondary outcomes with 95% confidence intervals (CI). Associations between baseline characteristics and outcomes are being examined using Cox regression modelling. Analyses were performed using SAS, Version 9.4 (SAS Institute Inc., Cary, North Carolina, USA).

Results: A total of 513 participants were enrolled at 6 sites (2021-2022) and 411 participants completed 90-day follow-up. Mean age was 58 years and 46% were females. Table 1 shows participant baseline characteristics. At 90 days, the cumulative incidence of symptomatic VTE was 0.90% (95%CI 0.30%-2.18%) (Table 2). The cumulative incidence of major bleeding was 0.20% (95%CI 0.20-1.10), CRNMB was 1.47% (95%CI 0.66-2.90), and mortality was 3.19% (95%CI 1.86-5.08).

Conclusion(s): In this unselected prospective cohort of adults hospitalized with COVID-19, the incidence of symptomatic VTE was low, consistent with findings from other studies. Further analyses currently underway may identify characteristics associated with increased risk.