key: cord-0721109-sostagrm authors: Eswaran, Harish; Jarmul, Jamie A.; Shaheen, Amy W.; Meaux, David; Long, Tristan; Saccoccio, Derek; Moll, Stephan title: Vascular thromboembolic events following COVID‐19 hospital discharge: Incidence and risk factors date: 2021-02-08 journal: Res Pract Thromb Haemost DOI: 10.1002/rth2.12485 sha: 7d6541893fc3f19238549cf399ba45025eb71c20 doc_id: 721109 cord_uid: sostagrm BACKGROUND: Coronavirus disease 2019 (COVID‐19) is associated with high rates of thromboembolic events in hospitalized patients. It remains to be determined if this risk persists following hospital discharge. METHODS: We conducted a retrospective cohort study of outpatients recently hospitalized for COVID‐19 to determine the incidence of vascular thromboembolic events within 30 days of discharge. We investigated the risk factors associated with these events, including intensive care admission, age, and anticoagulation. RESULTS: Among 447 patients hospitalized for COVID‐19, 2.0% experienced a vascular thromboembolic event within 30 days of discharge. No risk factor variable was significantly associated with an increased risk for these events. CONCLUSIONS: The incidence of vascular thromboembolic events following hospital discharge for COVID‐19 is low. These findings suggest against the routine use of postdischarge thromboprophylaxis in patients with COVID‐19. Coronavirus disease 2019 (COVID-19) is associated with a high incidence of vascular thromboembolic events (VaTEs) in hospitalized patients; 1 however, there are currently limited data on the incidence of VaTEs following hospital discharge. [2] [3] [4] The National Institutes of Health has issued guidelines recommending that postdischarge thromboprophylaxis be considered in certain high-risk patients, such as the elderly and patients with active malignancy or prior history of venous thromboembolism (VTE). 5 It remains uncertain whether the severity of COVID-19 is an independent risk factor for these events. We report the incidence of postdischarge venous and arterial thromboembolism after hospital admission for COVID-19 at our institution and investigated the risk factors associated with outpatient VaTEs. ESWARAN Et Al. Our study population consisted of patients hospitalized for COVID-19 at 1 of 11 hospitals in the University of North Carolina Health system and discharged between March 15 and July 4, 2020. COVID-19 was confirmed by the presence of a positive qualitative polymerase chain reaction test for severe acute respiratory distress syndrome coronavirus 2 obtained from nasopharyngeal or oropharyngeal swab samples. We excluded patients who died, were discharged to hospice or comfort care, screened positive when hospitalized for an unrelated condition, or were discharged on therapeutic anticoagulation for another indication. We report outcomes as incidence rates for the entire study popula- A total of 447 patients met the inclusion criteria. Background characteristics for the cohort are outlined in Table 1 and adjusted odds ratios for the logistic regression model can be found in Table 2 . We found that the incidence of postdischarge VaTE following admission for COVID-19 is low but not negligible. Our findings are in line with published literature reporting a cumulative VaTE incidence of 2.5%, with VTE rates ranging from 0.14% to 0.6% following COVID-19 hospital discharge. 2-4 Although we did not compare COVID to non-COVID discharges, other studies have also reported low 30-day postdischarge VTE incidence rates that do not significantly differ between medical patients with and without COVID-19. 2 The incidence of VaTEs in our study was higher following ICU admission, but this increase was not statistically significant. Confirmation in larger studies is needed to determine if ICU admission has an effect on outpatient VaTEs. This study has important limitations. Patients were not routinely screened for VaTEs and may have sought treatment for thrombotic complications outside the hospital system. These events may not have been captured by review of the electronic health record, leading to an underestimate of the true incidence. The designation of "symptomatic COVID-19" was left to individual providers, which may have led to the inclusion of patients with symptoms attributable to another medical condition and incidentally COVID positive. Guidelines for prescribing outpatient thromboprophylaxis evolved over the course of the pandemic, which may have led to inconsistent application of our institutional protocol (Figure 1 ). It is possible that patients thought to be at higher risk for VaTEs were discharged on prophylactic anticoagulation and that this may have led to a low incidence of VaTEs in this group. While we attempted to adjust for significant confounders in our logistic regression model (age and ICU admission), it is possible that there were other unmeasured risk factors that contributed to differences in use of postdischarge anticoagulation. In addition, we considered whether higher inpatient anticoagulation dosing may have contributed to the low incidence of outpatient events, but we found a comparable rate of outpatient VaTEs as studies that used standard dose prophylaxis in inpatients. [2] [3] [4] Finally, the low number of VaTEs in our patient cohort, as well as the confounding influence of postdischarge anticoagulation, limited our ability to investigate the impact of other risk factors on the outcome. Future analyses are needed to study the role of risk stratification and postdischarge anticoagulation in patients hospitalized for COVID-19. In summary, post-hospital discharge occurrence of venous or arterial thrombosis in patients hospitalized for COVID-19 infection is low, whether discharged with or without prophylactic anticoagulation. A randomized, controlled trial is needed to determine if the routine use of post-hospital discharge thromboprophylaxis is beneficial. HE, JJ, AS, DM, TL, and DS declare no conflicts of interest. SM has been a consultant for Bristol-Myers-Squibb. We thank the members of the UNC Health Alliance Population Health Services team for their support. HE, JJ, AS, and SM designed the research and wrote the manuscript. HE, JJ, DM, TL, and DS obtained data and analyzed the results. Stephan Moll @StephanHDMoll Incidence of venous thromboembolism in hospitalized patients with COVID-19 Postdischarge venous thromboembolism following hospital admission with COVID-19 Postdischarge thrombosis and hemorrhage in patients with COVID-19 Frequency of venous thromboembolism in 6513 patients with COVID-19: a retrospective study COVID-19 treatment guidelines: Antithrombotic therapy in patients with COVID-19