Evaluating the Effect of Inequalities in Oral Anti-coagulant Prescribing on Outcomes in People with Atrial Fibrillation

Background Whilst anti-coagulation is typically recommended for thromboprophylaxis in atrial fibrillation (AF), it is often never prescribed, or prematurely discontinued, due to concerns regarding bleeding risk. The aim of this study was to assess both stroke/systemic embolism (SSE) and bleeding risk, comparing people with AF who continue anticoagulation with those who stop transiently, stop permanently or never start. Methods This retrospective cohort study utilised linked Scottish administrative healthcare data to identify adults diagnosed with AF between January 2010 and April 2016, with a CHA 2 DS 2 - VASC score of ≥2. They were sub-categorised into cohorts based on anti-coagulant exposure: never started, continuous, discontinuous, and cessation. Inverse probability of treatment weighting-adjusted Cox regression and competing-risks regression were utilised to compare the risks of SSE and major bleeding between cohorts during a five year follow-up period. Sub-group analyses evaluating risk of SSE, bleeding and mortality, were undertaken for people commenced on anti-coagulation that experienced a major bleeding event Results Of an overall cohort of 47,427 people, 26,277 (55.41%) were never anti-coagulated, 7,934 (16.72%) received continuous anti-coagulation, 9,107 (19.2%) temporarily discontinued and 4,109 (8.66%) permanently discontinued. Initiation and continuation of anti-coagulation was less likely in people with a lower socio-economic status, elevated frailty score, or aged ≥75. SSE risk was significantly greater in those with discontinuous anti-coagulation, compared to continuous (SHR: 2.65; 2.39-2.94). In the context of a major bleeding event, there was no significant difference in bleeding risk between the cessation cohort compared to those that continued anti-coagulation (SHR 0.94; 0.42-2.14). Conclusion Our data suggest significant inequalities in anti-coagulation prescribing for people with AF, with substantial opportunity to improve initiation and continuation. Anti-coagulation decision-making must be patient-centered and recognise that discontinuation or cessation is associated with a substantial risk of thromboembolic events not offset by a reduction in bleeding. What is Known? Despite a high thromboembolic risk, anti-coagulation in people with atrial fibrillation is frequently not initiated, or prematurely discontinued What is New? Our data suggest considerable inequalities in anti-coagulation prescribing in people with atrial fibrillation; people with a lower socio-economic status, elevated frailty score, or aged ≥75 were less likely to initiate or continuation anti-coagulation Whilst non-initiation and cessation of anti-coagulation are associated with elevated thromboembolic risk, this risk is particularly high in people with atrial fibrillation that transiently discontinue anti-coagulation In the context of a major bleeding event, permanent discontinuation of anti-coagulation in people with atrial fibrillation is not associated with a significantly reduced risk of recurrent bleeding compared to those that are continuously anti-coagulated.