OpenSAFELY: impact of national guidance on switching anticoagulant therapy during COVID-19 pandemic

Abstract

BackgroundEarly in the COVID-19 pandemic, the National Health Service (NHS) recommended that appropriate patients anticoagulated with warfarin should be switched to direct-acting oral anticoagulants (DOACs), requiring less frequent blood testing. Subsequently, a national safety alert was issued regarding patients being inappropriately coprescribed two anticoagulants following a medication change and associated monitoring.ObjectiveTo describe which people were switched from warfarin to DOACs; identify potentially unsafe coprescribing of anticoagulants; and assess whether abnormal clotting results have become more frequent during the pandemic.MethodsWith the approval of NHS England, we conducted a cohort study using routine clinical data from 24 million NHS patients in England.Results20 000 of 164 000 warfarin patients (12.2%) switched to DOACs between March and May 2020, most commonly to edoxaban and apixaban. Factors associated with switching included: older age, recent renal function test, higher number of recent INR tests recorded, atrial fibrillation diagnosis and care home residency. There was a sharp rise in coprescribing of warfarin and DOACs from typically 50–100 per month to 246 in April 2020, 0.06% of all people receiving a DOAC or warfarin. International normalised ratio (INR) testing fell by 14% to 506.8 patients tested per 1000 warfarin patients each month. We observed a very small increase in elevated INRs (n=470) during April compared with January (n=420).ConclusionsIncreased switching of anticoagulants from warfarin to DOACs was observed at the outset of the COVID-19 pandemic in England following national guidance. There was a small but substantial number of people coprescribed warfarin and DOACs during this period. Despite a national safety alert on the issue, a widespread rise in elevated INR test results was not found. Primary care has responded rapidly to changes in patient care during the COVID-19 pandemic.

Deaths from cardiovascular disease involving anticoagulants: a systematic synthesis of coroners’ case reports

“…During the COVID-19 pandemic, patients were switched from warfarin to other oral anticoagulants, given the need for less frequent blood testing. 37 Drugs such as andexanet alfa could prove critical in the outcome of patients with severe bleeding during treatment with apixaban or rivaroxaban. Since the coroner expressed concerns (case: 2018–0032), 38 NICE conducted an appraisal of andexanet alfa for reversing anticoagulation 39 and published guidance on 12 May 2021.…”

Edoxaban Versus Low-Molecular-Weight Heparin in Hospitalized COVID-19 Patients With Atrial Fibrillation

“… 18 In addition, during the COVID-19 pandemic, anticoagulants were more frequently switched from warfarin to DOACs. 19 Remarkably, available information remains very scarce, even though some studies analyzing the role of edoxaban in patients with COVID-19 are ongoing. Thus, HERO-19 (Hamburg Edoxaban for Anticoagulation in COVID-19 Study, NCT04542408) is currently evaluating whether an intensive anticoagulation strategy using edoxaban (in-hospital, therapeutic LMWH dose, followed by edoxaban) is superior to standard of care (low-dose LMWH, followed by ambulatory no anticoagulation), and the CONVINCE study (CorONa Virus edoxabaN ColchicinE COVID-19, NCT04516941) has been terminated owing to the insufficient rate of patient accrual and newly available scientific evidence.…”

Barriers and enablers to healthcare system uptake of direct oral anticoagulants for stroke prevention in atrial fibrillation: a qualitative interview study with healthcare professionals and policy makers in England

“…During the pandemic, there was a national guidance on switching patient from warfarin to DOACs to minimise the risk of potential virus transmission during warfarin clinic appointments, 26 which drove an increase in DOAC prescribing. 27 …”