Impact of thromboprophylaxis on hospital acquired thrombosis following discharge in patients admitted with COVID-19: Multicentre observational study in the UK

Post-discharge thromboprophylaxis in patients admitted with COVID- 19 remains controversial. We aimed to determine the impact of thromboprophylaxis on hospital acquired thrombosis (HAT) in patients (=18 years) discharged following admission for COVID- 19 in an observational study across 26 NHS Trusts in the UK (01.04.2020- 31.12.2021). Overall, 8895 patients were included to the study: 971 patients were discharged with thromboprophylaxis and propensity score matched (PSM) with a desired ratio of 1:1, from patients discharged without thromboprophylaxis. Patients with heparin induced thrombocytopenia, major bleeding during admission and pregnant women were excluded. As expected from 1:1 PSM, no difference was ob-served in parameters between the two groups, including duration of hospital stay, except the thromboprophylaxis group had a significantly higher proportion who had received therapeutic dose anticoagulation during admission. There were no dif-ferences in the laboratory parameters especially D-dimers between the two groups at admission or discharge. Median duration of thromboprophylaxis following dis-charge from hospital was 4 weeks (1- 8 weeks). No difference was found in HAT in patients discharged with TP versus no TP (1.3% vs. 0.92%, p = 0.52). Increasing age and smoking significantly increased the risk of HAT. Many patients in both cohorts had raised D- dimer at discharge but D- dimer was not associated with increased risk of HAT.

Automated summary

The controversy of post-discharge thromboprophylaxis in COVID-19 patients remains. This observational study across 26 NHS Trusts aimed to determine the impact of thromboprophylaxis on hospital acquired thrombosis (HAT) in discharged patients. The study found no difference in HAT between patients discharged with and without thromboprophylaxis, but increasing age and smoking significantly increased the risk of HAT.