Adherence to antithrombotic therapy guidelines improves mortality among elderly patients with atrial fibrillation: insights from the REPOSI study

Background: Atrial fibrillation (AF) is associated with a substantial risk of thromboembolism and mortality, significantly reduced by oral anticoagulation. Adherence to guidelines may lower the risks for both all cause and cardiovascular (CV) deaths. Methods: Our objective was to evaluate if antithrombotic prophylaxis according to the 2012 European Society of Cardiology (ESC) guidelines is associated to a lower rate of adverse outcomes. Data were obtained from REPOSI; a prospective observational study enrolling inpatients aged ≥65 years. Patients enrolled in 2012 and 2014 discharged with an AF diagnosis were analysed. Results: Among 2535 patients, 558 (22.0 %) were discharged with a diagnosis of AF. Based on ESC guidelines, 40.9 % of patients were on guideline-adherent thromboprophylaxis, 6.8 % were overtreated, and 52.3 % were undertreated. Logistic analysis showed that increasing age (p = 0.01), heart failure (p = 0.04), coronary artery disease (p = 0.013), peripheral arterial disease (p = 0.03) and concomitant cancer (p = 0.003) were associated with non-adherence to guidelines. Specifically, undertreatment was significantly associated with increasing age (p = 0.001) and cancer (p <0.001), and inversely associated with HF (p = 0.023). AF patients who were guideline adherent had a lower rate of both all-cause death (p = 0.007) and CV death (p = 0.024) compared to those non-adherent. Kaplan–Meier analysis showed that guideline-adherent patients had a lower cumulative risk for both all-cause (p = 0.002) and CV deaths (p = 0.011). On Cox regression analysis, guideline adherence was independently associated with a lower risk of all-cause and CV deaths (p = 0.019 and p = 0.006). Conclusions: Non-adherence to guidelines is highly prevalent among elderly AF patients, despite guideline-adherent treatment being independently associated with lower risk of all-cause and CV deaths. Efforts to improve guideline adherence would lead to better outcomes for elderly AF patients.