Evaluation of antithrombotic use and COVID-19 outcomes in a nationwide atrial fibrillation cohort.

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OBJECTIVE: To evaluate antithrombotic (AT) use in individuals with atrial fibrillation (AF) and at high risk of stroke (CHA2DS2-VASc score ≥2) and investigate whether pre-existing AT use may improve COVID-19 outcomes. METHODS: Individuals with AF and CHA2DS2-VASc score ≥2 on 1 January 2020 were identified using electronic health records for 56 million people in England and were followed up until 1 May 2021. Factors associated with pre-existing AT use were analysed using logistic regression. Differences in COVID-19-related hospitalisation and death were analysed using logistic and Cox regression in individuals with pre-existing AT use versus no AT use, anticoagulants (AC) versus antiplatelets (AP), and direct oral anticoagulants (DOACs) versus warfarin. RESULTS: From 972 971 individuals with AF (age 79 (±9.3), female 46.2%) and CHA2DS2-VASc score ≥2, 88.0% (n=856 336) had pre-existing AT use, 3.8% (n=37 418) had a COVID-19 hospitalisation and 2.2% (n=21 116) died, followed up to 1 May 2021. Factors associated with no AT use included comorbidities that may contraindicate AT use (liver disease and history of falls) and demographics (socioeconomic status and ethnicity). Pre-existing AT use was associated with lower odds of death (OR=0.92, 95% CI 0.87 to 0.96), but higher odds of hospitalisation (OR=1.20, 95% CI 1.15 to 1.26). AC versus AP was associated with lower odds of death (OR=0.93, 95% CI 0.87 to 0.98) and higher hospitalisation (OR=1.17, 95% CI 1.11 to 1.24). For DOACs versus warfarin, lower odds were observed for hospitalisation (OR=0.86, 95% CI 0.82 to 0.89) but not for death (OR=1.00, 95% CI 0.95 to 1.05). CONCLUSIONS: Pre-existing AT use may be associated with lower odds of COVID-19 death and, while not evidence of causality, provides further incentive to improve AT coverage for eligible individuals with AF.


Funder: British Medical Association; FundRef: http://dx.doi.org/10.13039/501100000374

Funder: UK Research and Innovation; FundRef: http://dx.doi.org/10.13039/100014013

Funder: NIHR University College London Hospitals Biomedical Research Centre

Funder: AstraZeneca; FundRef: http://dx.doi.org/10.13039/100004325

Funder: NIHR Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London, London, UK

Funder: UK Research and Innovation London Medical Imaging & Artificial Intelligence Centre for Value Based Healthcare

Funder: NIHR Applied Research Collaboration South London (NIHR ARC South London) at King’s College Hospital NHS Foundation Trust

COVID-19, atrial fibrillation, drug monitoring, electronic health records, epidemiology, Aged, Anticoagulants, Atrial Fibrillation, COVID-19, Female, Fibrinolytic Agents, Humans, Risk Assessment, Risk Factors, Stroke, Warfarin
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Medical Research Council (MR/L003120/1)
British Heart Foundation (None)
British Heart Foundation (RG/18/13/33946)
National Institute for Health and Care Research (IS-BRC-1215-20014)
British Heart Foundation (SP/18/3/33801)
Medical Research Council (MC_PC_17214)
MRC (via University College London (UCL)) (MC_PC_20059)