Initiation patterns of anticoagulants for atrial fibrillation among older UK adults with and without chronic kidney disease, 2010–2020

Abstract

Background There is a paucity of data on the initiation patterns of anticoagulants among older atrial fibrillation patients with and without chronic kidney disease (CKD).Setting and methods We used the UK Clinical Practice Research Datalink (2010–2020) to conduct a retrospective cohort study to evaluate anticoagulant initiation patterns for older adults (≥65 years) with CKD (N=18 421) and without CKD (N=41 901), categorised by severity of CKD: stages 3a, 3b and 4, and initiation dose by respective direct oral anticoagulant (DOAC).Results Over the study period, warfarin initiations sharply declined and were replaced by DOACs regardless of CKD status or stage. By 2020, patients with CKD were modestly more likely (8.8% difference) to initiate apixaban compared with those without CKD (58.8% vs 50.0%; p<0.01). Among patients with CKD, those with stages 3a and 3b CKD had higher apixaban initiations compared with stage 4 CKD (56.9% and 64.6% vs 52.9%, respectively; p<0.01). Conversely, patients with stage 4 CKD were over three times more likely to initiate warfarin (14.7%) compared with those with stage 3a (2.6%) and 3b (4.0%) CKD (p<0.01). Throughout the study period, there was a rise in the proportion of patients initiating the higher 10 mg daily dose for apixaban, with an increase of 20.6% (from 64.3% in 2013 to 84.9% in 2020; p value for trend <0.01) among patients without CKD, and 21.8% (53.1% to 74.9%; p<0.01), 24.4% (18.8% to 43.2%; p<0.01) and 18.5% (0.0% to 18.2%; p<0.01) among patients with stages 3a, 3b and 4 CKD, respectively.Conclusions and relevance Initiation of DOACs increased regardless of CKD status and stage, although with a reduced magnitude in severe CKD. Apixaban emerged as the preferred agent, with a secular trend towards the higher initiation dose in all subgroups. These findings illuminate evolving trends and priorities in anticoagulant preferences among patients with and without CKD.