Clinical outcomes and the impact of prior oral anticoagulant use in patients with coronavirus disease 2019 admitted to hospitals in the UK - a multicentre observational study

Coagulation dysfunction and thrombosis are major complications in patients with coronavirus disease 2019 (COVID-19). Patients on oral anticoagulants (OAC) prior to diagnosis of COVID-19 may therefore have better outcomes. In this multicentre observational study of 5 883 patients (>= 18 years) admitted to 26 UK hospitals between 1 April 2020 and 31 July 2020, overall mortality was 29 center dot 2%. Incidences of thrombosis, major bleeding (MB) and multiorgan failure (MOF) were 5 center dot 4%, 1 center dot 7% and 3 center dot 3% respectively. The presence of thrombosis, MB, or MOF was associated with a 1 center dot 8, 4 center dot 5 or 5 center dot 9-fold increased risk of dying, respectively. Of the 5 883 patients studied, 83 center dot 6% (n = 4 920) were not on OAC and 16 center dot 4% (n = 963) were taking OAC at the time of admission. There was no difference in mortality between patients on OAC vs no OAC prior to admission when compared in an adjusted multivariate analysis [hazard ratio (HR) 1 center dot 05, 95% confidence interval (CI) 0 center dot 93-1 center dot 19; P = 0 center dot 15] or in an adjusted propensity score analysis (HR 0 center dot 92 95% CI 0 center dot 58-1 center dot 450; P = 0 center dot 18). In multivariate and adjusted propensity score analyses, the only significant association of no anticoagulation prior to diagnosis of COVID-19 was admission to the Intensive-Care Unit (ICU) (HR 1 center dot 98, 95% CI 1 center dot 37-2 center dot 85). Thrombosis, MB, and MOF were associated with higher mortality. Our results indicate that patients may have benefit from prior OAC use, especially reduced admission to ICU, without any increase in bleeding.