Blood. 2021 Apr 6:blood.2020010529. doi: 10.1182/blood.2020010529. Online ahead of print.
Thromboembolic events including venous thromboembolism (VTE), arterial thromboembolism (ATE), and mortality from sub-clinical thrombotic events occur frequently in COVID-19 inpatients. Whether the risk extends post-discharge has been controversial. Our prospective registry included consecutive COVID-19 patients hospitalized within our multihospital system from March 1st - May 31st 2020. We captured demographics, comorbidities, laboratory parameters, medications, post-discharge thromboprophylaxis, and 90-day outcomes. Data from electronic health records, health informatics exchange, a radiology database, and telephonic follow-up were merged. The primary outcome was a composite of adjudicated VTE, ATE, and all-cause mortality (ACM). The principal safety outcome was major bleeding (MB). Among 4,906 patients (53.7% male) mean age was 61.7 years. Comorbidities included hypertension (38.6%), diabetes (25.1%), obesity (18.9%), and cancer history (13.1%). Post-discharge thromboprophylaxis was prescribed in 13.2%. VTE rate was 1.55%, ATE 1.71%, ΑCM 4.83%, and MB 1.73%. The composite primary outcome rate was 7.13% and was significantly associated with advanced age (OR: 3.66, 95%CI: 2.84-4.71), prior VTE (OR: 2.99, 95%CI: 2.00-4.47), ICU stay (OR: 2.22, 95%CI: 1.78-2.93), chronic kidney disease (CKD) (OR: 2.10, 95%CI: 1.47-3.0), peripheral arterial disease (OR: 2.04, 95%CI: 1.10-3.80), carotid occlusive disease (OR: 2.02, 95%CI: 1.30-3.14), IMPROVE-DD VTE score ≥4 (OR: 1.51, 95%CI: 1.06-2.14), and coronary artery disease (OR: 1.50, 95%CI: 1.04-2.17). Post-discharge anticoagulation was significantly associated with reducing the primary outcome (OR: 0.54, 95%CI: 0.47-0.81). Post-discharge VTE, ATE, and ACM occur frequently following COVID-19 hospitalization. Advanced age, cardiovascular risk factors, CKD, IMPROVE-DD VTE score ≥4, and ICU stay increase risk. Post-discharge anticoagulation reduced risk by 46%.