Clinical Characteristics, Patterns of Use, and incidence of Adverse Events in Patients With Nonvalvular Atrial Fibrillation Treated With Oral Anticoagulants in Colombia.

Abstract

The aim was to analyze the characteristics, treatment patterns, and clinical outcomes of Colombian patients with non-valvular atrial fibrillation (NVAF) under treatment with oral anticoagulants (OAs). Retrospective cohort in patients with NVAF identified from a drug dispensing database, aged ≥18 years, with first prescription of an OA (index) between January/2013 and June/2018, and a follow-up until June/2019. Data from the clinical history, pharmacological variables, and outcomes were searched. International Classification of Diseases-10 codes were used to identify the patient sample and outcomes. Patients were followed until a general composite outcome of effectiveness (thrombotic events), bleeding/safety or persistence (switch/discontinuation of anticoagulant) events. Descriptive and multivariate analyzes (Cox regressions comparing warfarin and direct oral anticoagulants-DOACs) were carried out. A total of 2076 patients with NVAF were included. The 57.0% of patients were women and the mean age was 73.3±10.4 years. Patients were followed for a mean of 2.3±1.6 years. 8.7% received warfarin before the index date. The most frequent OA was rivaroxaban (n=950; 45.8%), followed by warfarin (n=459; 22.1%) and apixaban (n=405; 19.5%). Hypertension was present in 87.5% and diabetes mellitus in 22.6%. The mean CHA2DS2-VASc Score was 3.6±1.5. The 71.0% (n=326/459) of the warfarin patients presented the general composite outcome, and 24.6% of those with DOACs (n=397/1617). The main effectiveness and safety outcomes were stroke (3.1%) and gastrointestinal bleeding (2.0%) respectively. There were no significant differences between patients with warfarin and DOACs regarding thrombotic events (HR: 1.28; 95% CI: 0.68-2.42), but warfarin was associated with higher bleeding/safety events (HR: 4.29; 95% CI: 2.82-6.52) and persistence events (HR: 4.51; 95% CI: 3.81 -5.33). The patients with NVAF in this study were mainly older adults with multiple comorbidities. Compared to warfarin, DOACs were found to be equally effective, but safer and had a lower probability of discontinuation or switch.