Post hospital discharge thrombosis in patients with COVID-19

Background : Coronavirus disease 2019 (COVID-19) is associated with a high incidence of thrombotic events during hospitalization, however, the need for postdischarge thromboprophylaxis remains unclear. Aims : To quantify the 90-day post hospital discharge rates of venous and arterial thromboembolism in COVID-19. Methods : A retrospective single institution observational study of adult patients hospitalized with COVID-19 confirmed by positive SARS-CoV-2 testing from 3/1/2020 to 8/31/2020. Patients were excluded if they: remained hospitalized at time of analysis, died during hospitalization or were discharged to hospice. For patients with multiple admissions related to COVID-19, the first admission was included. Thromboembolism was identified with ICD-10 codes up to 90 days of discharge: pulmonary embolism (PE: I26), deep vein thrombosis (DVT: I82), portal vein thrombosis (I81), intracranial venous thrombosis (I67),transient ischemia attack (TIA: G45), stroke (I63), acute coronary syndrome (ACS: I20, I21, I22, I24), intracardiac thrombosis (I23, I51.3), and acute limb ischemia (I74). Results : Of 1653 hospitalized patients, 26 (1.6%) developed post discharge venous thrombosis events (12 PE, 13 DVT and 1 portal vein thrombosis). Eleven (0.7%) post discharge arterial thrombosis events were observed(1 TIA and 10 ACS). The risk of VTE decreases with time (Mann-Kendall trend test P -value < 0.001) with median event time 15.5 days (IQR: 6-27). The risk of arterial thrombosis is constant with time (Mann-Kendall trend test P -value = 0.86) with median event time 54 days (IQR: 24-65). Conclusions : The rate thromboembolism is relatively low among COVID-19 patients after they leave the hospital. Results of ongoing randomized trials of the efficacy of post-discharge anticoagulation prophylaxis are eagerly awaited.