Challenges in Performing Real-World Evidence Studies in Low-Middle Income Countries: the EdoBRA Study

In 1991, Wolf et al. on the Framingham study demonstrated that atrial fibrillation (AF) constitutes an independent risk factor for ischemic stroke. Hart et al., in a meta-analysis, confirmed warfarin’s effectiveness in lowering stroke risk by 64% in AF patients. A slight increase in major extracranial hemorrhage was observed, which did not impact overall efficacy. Unpredictable pharmacokinetics, interactions, and INR monitoring needs have limited warfarin use. In low-middle income countries (LMICs) like Brazil, socio-economic disparities affected warfarin use in AF patients.

Direct oral anticoagulants (DOACs) were introduced to overcome the barriers associated with warfarin. All DOACs showed strong stroke prevention compared to warfarin. Edoxaban in the ENGAGE AF-TIMI 48 trial was non-inferior to warfarin in safety and superior in preventing hemorrhagic strokes. Latin American patients showed higher hemorrhage and mortality rates compared to other regions. In addition, considerations of cost, renal monitoring, DOACs in AF subpopulations, and reversal agents for hemorrhage highlight the importance of tailoring therapy based on patient-specific risks.

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