Estimating the Burden of Venous and Arterial Thrombotic Events in Hospitalized Adults with COVID-19; A National Multicenter Cohort Study
Authors: Patell Rushad , Angelini Dana E. , Ellsworth Stacy R , Lewis Paul , Lee James C , Nutescu Edith A. , Amin Alpesh , Witt Daniel M , Betensky Marisol , Goldenberg Neil , Kouides Peter , Attia, MD Doaa , Mourany Lyla , Lake Leslie , Rosovsky Rachel P. , Khorana Alok A. , Kaatz Scott 
Published: December 2023

Background:
Patients infected with Coronavirus Disease 2019 (COVID-19) have clinical and laboratory features consistent with a hypercoaguable state, particularly in more severely ill patients that require hospitalization. However, estimates of thrombotic complications in this high risk population vary widely. A geographic representative cohort to explore the rates of thrombotic events in patients hospitalized with COVID-19 in the United States would be useful to better understand the burden of thrombosis in this population. We aimed to assess the rates of venous and arterial thrombosis events during hospitalization in patients with COVID-19 in a national multicenter cohort study.
Methods:
We conducted a retrospective cohort study of hospitalized patients diagnosed with COVID-19 from January 1 2020 to January 2023. IRB approval was obtained at each site. Inclusion criteria included adults (&gt; 21 years), hospitalized for &gt;1 day and laboratory confirmation of polymerase chain reaction testing of severe acute respiratory syndrome coronavirus 2. Data were extracted by participating centers in a pre-specified instrument from the electronic medical record at each institution and pooled prior to analysis. Data sources included manual extraction by study investigators in 7 sites and electronic extraction based on billing codes at one site (Cleveland Clinic). Primary outcome was venous thrombotic events, including deep vein thrombosis (DVT), pulmonary embolism (PE). Unusual sites including splanchnic vein thrombosis and cerebral venous thrombosis were included if objectively demonstrated on imaging. Arterial thrombotic events including ischemic stroke, acute coronary syndrome were included as secondary outcomes. Data are presented as proportions, with binomial 95% confidence intervals (CI).
Results:
We included 33,769 patients from eight medical centers across the United States. Participating hospitals included all four census regions from the North East (Beth Israel Deaconess Medical Center, MA (n=1021) Rochester Regional Hospital, NY (n=99)), South (John Hopkins Medical Institute, ML (n=334); Baycare Health System, FL (n=3734), MidWest (Cleveland Clinic Foundation, OH (n=25467); Henry Ford Health System, MI (973); University of Illinois, IL (1192)) and West (University of California, CA (n=613)). (Figure)
Of the total 33,433 hospitalized patients with COVID-19 included, 1684 patients developed a venous thrombotic event during the index hospitalization (5.0%, 95% CI 4.8-5.2) and 261 developed an arterial thrombotic event (0.8%, 95% CI, 95% CI 0.7-0.9). Rates of venous events by individual sites ranged from 2.6-8% and arterial events from 0.3-6.6%.
Conclusion:
In this national multicenter cohort study that included academic and community hospitals from all four US census regions, we estimated the rates of VTE were over five times more frequent than arterial events in hospitalized patients with COVID-19. Accurate estimates of thrombotic rates and trends can help plan targeted interventions related to strategies around thromboprophylaxis interventions and resource allocation for future surges of COVID-19 cases.