Association between oral anticoagulants and COVID-19-related outcomes: a population-based cohort study.

BACKGROUND: Early evidence has shown that anticoagulant reduces the risk of thrombotic events in those infected with COVID-19. However, evidence of the role of routinely prescribed oral anticoagulants (OACs) in COVID-19 outcomes is limited. AIM: To investigate the association between OACs and COVID-19 outcomes in those with atrial fibrillation and a CHA2DS2-VASc score of 2. DESIGN AND SETTING: On behalf of NHS England, a population-based cohort study was conducted. METHOD: The study used primary care data and pseudonymously-linked SARS-CoV-2 antigen testing data, hospital admissions, and death records from England. Cox regression was used to estimate hazard ratios (HRs) for COVID-19 outcomes comparing people with current OAC use versus non-use, accounting for age, sex, comorbidities, other medications, deprivation, and general practice. RESULTS: Of 71 103 people with atrial fibrillation and a CHA2DS2-VASc score of 2, there were 52 832 current OAC users and 18 271 non-users. No difference in risk of being tested for SARS-CoV-2 was associated with current use (adjusted HR [aHR] 0.99, 95% confidence interval [CI] = 0.95 to 1.04) versus non-use. A lower risk of testing positive for SARS-CoV-2 (aHR 0.77, 95% CI = 0.63 to 0.95) and a marginally lower risk of COVID-19-related death (aHR, 0.74, 95% CI = 0.53 to 1.04) were associated with current use versus non-use. CONCLUSION: Among those at low baseline stroke risk, people receiving OACs had a lower risk of testing positive for SARS-CoV-2 and severe COVID-19 outcomes than non-users; this might be explained by a causal effect of OACs in preventing severe COVID-19 outcomes or unmeasured confounding, including more cautious behaviours leading to reduced infection risk.

Impact of the COVID-19 pandemic on England's national prescriptions of oral vitamin K antagonist (VKA) and direct-acting oral anticoagulants (DOACs): an interrupted time series analysis (January 2019-February 2021).

BACKGROUND: Direct-acting oral anticoagulants (DOACs) were developed as an alternative to warfarin to treat and prevent thromboembolism, including stroke prevention in non-valvular atrial fibrillation patients. The COVID-19 pandemic could increase the risk of stroke and/or the risk of bleeding in patients due to nonadherence or sub/supra-optimal dosing. OBJECTIVE: To investigate DOAC prescription trends in England's community settings during the complete first wave of COVID-19 pandemic. METHODS: Descriptive and interrupted time series (ITS) analyses were conducted to examine the prescription patterns of DOACs (dabigatran, rivaroxaban, apixaban and edoxaban) and warfarin for primary care patients in the English Prescribing Dataset from January 2019 to February 2021, with March 2020 as the cut-off point. RESULTS: A 19% increase in mean DOAC's accompanied with 20% warfarin prescriptions decline was observed. ITS modelling showed an increase in DOAC prescription volume in March 2020 (+7 million items, p = 0.008). The pre-existing upward trend in DOAC prescriptions slowed during the period (-427,000 items, p = 0.007). Apixaban was the most frequently used DOAC and had the largest step-change in March 2020 (+5 million items, p = 0.010). The mean monthly combined cost of DOACs and warfarin was higher during the period. DOAC prescription trends were consistent across England's regions. Conclusion: The overall oral anticoagulants use in this period was lower than expected, indicating a medical needs gap, possibly due to adherence issues. The potential clinical and logistical consequences warrant further study to identify contributing factors and mitigate avoidable risks.

Breakthrough venous thromboembolic events in five patients with COVID-19 on direct oral anticoagulants.

WHAT IS KNOWN AND OBJECTIVE: Coronavirus disease 2019 (COVID-19) is associated with increased risk of venous thromboembolism (VTE). Guidance for VTE prophylaxis continues to evolve, including addressing direct oral anticoagulants (DOACs) continued upon hospitalization. CASE SUMMARIES: We present 5 patients hospitalized for COVID-19 while on DOACs. Four patients had atrial fibrillation and had a previous VTE. Four patients developed acute VTE and one developed stroke-like symptoms. Monitoring D-dimer assisted with the detection of VTE. Three patients died, and two were discharged alive. WHAT IS NEW AND CONCLUSION: Therapeutic failure with DOACs appears to be commonplace in COVID-19. Further research is needed to determine whether there is an underlying cause to this association.