Real-life behaviour of direct oral anticoagulants in a Spanish cohort with non-valvular atrial fibrillation: Refase Registry

Abstract

Aim: To analyse the effectiveness and safety of DOAC (direct oral anticoagulants) in nonvalvular atrial fibrillation (NVAF) patients attending clinical practice. Methods: Retrospective study of AF patients who started treatment with DOAC from January 1, 2013 to December 31, 2016 in three Spanish hospitals. Mean follow up was 1.6 years. The primary outcomes were rates of all-cause death, ischemic stroke and bleeding. We also studied these outcomes depending on correct dosage adjustment and standard/adjusted dose. Results: The study included 2494 patients (age 76.0 ± 9.5 years, CHA₂DS₂-VASc =4.0 ± 1.6). The most prescribed DOAC was rivaroxaban (41.1%). Patients taking dabigatran were the youngest (mean age 73.1 ± 10.3 years), with better kidney function (mean CrCl 80.6 ± 35.8 ml/min) and lower CHA₂DS₂-VASc (3.7 ± 1.4) and HAS-BLED (2.1 ± 0.9) scores. Patients taking apixaban were the oldest, and had the highest CHA2DS2-VASc and HAS-BLED scores (4.3 ± 1.6 and 2.6 ± 0.9 respectively). Rates of stroke/major bleeding/intracranial bleeding were 1.8/3.0/0.3 events per 100 patient-years, respectively, with no differences among DOAC. Based on dose adjustment according to technical data, we observed that 517 patients (23.5%) received DOAC doses inconsistent with labelling (p < 0.001) and, within this group, underdosed patients had a higher death rate although it did not reach a significant result after multivariate adjustment. Conclusion: Our results of safety and efficacy are very similar to those of other previously published national registries. There were no differences among the different types of DOAC regarding outcomes. However, it was found that people taking the adjusted dose of the drug seemed to have a higher risk of death. A non-negligible proportion of patients received DOAC doses inconsistent with labelling (mostly underdose).