Thromboembolic Outcomes of Hospitalized COVID-19 Patients in the 90-Day Post-Discharge Period: Early Data from the Northwell CORE-19 Registry
Authors: Giannis Dimitrios , Allen Steven L. , Davidson Anne , Marder Galina S. , Flint Sarah , Garrett David , Thakur Richa , Snyder Matthew , Ghiuzeli Cristina , McGinn Thomas G. , Davidson Karina W. , Qiu Michael , Barish Matthew , Spyropoulos Alex C. 
Published: November 2020

Introduction
Thromboembolic outcomes have emerged as an important issue in sick hospitalized patients with COVID-19. Multiple pathogenetic mechanisms for thrombosis have been implicated, including endothelial dysfunction, increased von Willebrand factor (vWF), interleukin-6 release, and activation of/interaction between macrophages, monocytes, endothelial cells, platelets and lymphocytes. The actual rate of arterial and venous thromboembolic events (ATE and VTE) in hospitalized patients with COVID-19, especially in the immediate post-hospital discharge period, has not been fully elucidated, with most of the data derived from retrospective studies with small sample sizes.
Methods
Against this background, we have designed and implemented an ongoing prospective registry (CORE-19) consisting of 11,249 consecutive hospitalized patients with COVID-19 from March 1st 2020 through May 31st 2020 using data derived from the Northwell Health System and the COVID-19 Research Consortium to study through 90-days post-discharge the rate of VTE and ATE, major bleeding, all-cause mortality, and other complications. We are capturing data of interest including demographic characteristics, co-morbidities, relevant medications, hospital setting, in-hospital treatment, thromboprophylaxis usage, key laboratory parameters, and 90-day thromboembolic and other key outcomes. A unified data repository (datamart) of hospitalized COVID-19 patients across multiple datasets from electronic health records, health informatics exchange, a dedicated radiology database, and a standardized data collection tool in REDCap, that includes telephonic calls up to 90 days post-discharge, is being implemented. A common data model (CDM) is utilized to ensure semantic interoperability between data originating from disparate sources. Northwell Health protocols stipulate the use of post-discharge low-molecular weight heparin, direct oral anticoagulants, or baby aspirin in hospitalized COVID-19 patients with high thrombotic risk features.
Results
Our cohort as of August 7, 2020 consists of complete follow up in 4,100 patients with a mean age of 61.0 years (SD: 17.0) with 54.7% males (Table 1). Preliminary data show an all-cause mortality rate of 4.29%, an overall thromboembolic rate of 3.51% (2.41% VTE and 1.10% ATE), a major bleeding rate of 1.61%, and a rehospitalization rate of 12.85%. Of patients with either DVT or PE post-discharge, 13.43% (9/67) died. The full dataset, including risk factors, comorbidities, key in-hospital and post-discharge medications including anticoagulant and antiplatelet agents, will be available at the time of presentation to the ASH congress.
Conclusion
Our ongoing registry is a large prospective study evaluating the rate of overall thromboembolic complications and all-cause mortality in hospitalized COVID-19 patients through 90 days post discharge. Current rates of thromboembolic events signify the importance of post-discharge surveillance and, potentially, post-discharge extended thromboprophylaxis, in this acutely ill medical population.

Disclosures
Allen: Bristol Myers Squibb: Current equity holder in publicly-traded company. Spyropoulos:Janssen, Boehringer Ingelheim, Bayer, BMS, Portola, ATLAS Group: Consultancy; Janssen, Boehringer Ingelheim: Research Funding.