IJCS | Volume 33, Nº1, January / February 2019

DOI: https://doi.org/10.36660/ijcs.20190003 Atrial fibrillation (AF) is themost prevalent arrhythmia in the world. 1 It is considered a current epidemic and one of the main causes of ischemic stroke, usually with severe and debilitating conditions, and is responsible for systemic cardioembolic phenomena, increased number of cases of congestive heart failure (CHF), cognitive impairment related to silent embolic phenomena, and increased overall mortality in affected patients. Vitamin K antagonists (VKA) represented in the vast majority of studies with warfarin have been widely used for many years; however, they have complex adherence due to several factors, including the need for frequent INR monitoring, regular dose adjustments for maintaining a suitable time in therapeutic range (TTR) (>= 70%) and interactions with a number of drugs and foods, which contributed to its ever decreasing use. 2 Direct-acting anticoagulants (DACs), represented by dabigatran, rivaroxaban, apixaban and, more recently, edoxaban, offer an alternative to VKA, without the disadvantages presented by the latter. DACs have been increasingly used for the prevention of ischemic stroke and systemic embolic phenomena in non-valvular AF, with efficacy and safety confirmed in randomized multicenter non-inferiority studies with an overwhelming number of patients included. 3 Besides, in real-life studies, the results of phase III studies have been confirmed, demonstrating advantages of using DACs even in older populations, with confirmed reduction in intracranial hemorrhage and some DACs demonstrating superiority in mortality compared to warfarin. Nevertheless, although the introduction of DACs has promoted the use of anticoagulation in patients with non-valvular AF (absence of moderate to severe mitral stenosis and/or presence of mechanical valve), and despite the availability of national and international guidelines on the subject, 4-6 the application of these guidelines in clinical practice is still far from desired worldwide, either due to the use of incorrect doses (usually below the recommended ones) or to inadequate use due to lack of knowledge of related drug interactions and fear of bleeding in the older population. In this retrospective observational study, which collected data from an electronic medical record, conducted at a single center of a private tertiary hospital in Salvador (BA), Geraldes et al. 7 evaluated the predictors of oral anticoagulation in patients with non-valvular AF and atrial flutter from 2011 to 2016 and how DACs are being incorporated in this context. A well-written original article where the authors evaluated 377 patients, mostly with paroxysmal AF, with a high rate of comorbidities such as: SAH, DM, history of HF, AMI and stroke were separated into two groups: with and without anticoagulants. The anticoagulated group was divided into use of DACs andwarfarin, and the following variables were listed: previous paroxysmal AF, presence of CHF, serum creatinine, EF, LA diameter, presence of biological prosthesis, moderate valvular disease and history of previous electrical or chemical cardioversion. The authors demonstrated that, during these 5 years of follow-up, therewas a significant increase in the number of patients anticoagulatedwithDACs (from29% to 70%—a relative increase of 144.8% and an annual incorporation of 10.4%) and a progressive decrease in warfarin use (36% to 17%) in the population evaluated, with a drop in antiplatelet use alone (21% to 6%), confirming the initial impression that the increase in DAC prescriptions has accelerated the decline inwarfarinprescriptions. It isworth noting that the use of antiplatelets alone in AF does not protect from ischemic stroke/thromboembolism (ET) in 65 EDITORIAL International Journal of Cardiovascular Sciences. 2020;33(1):65-67 Mailing Address: Ana Inês da Costa Bronchtein Rua Rainha Guilhermina, 23/401. Postal Code: 22441120, Leblon Rio de Janeiro – RJ – Brazil. E-mail: a.bronchtein@gmail.com Challenges for Anticoagulation in Atrial Fibrillation Ana Inês da Costa Bronchtei n Hospital Copa D’or – Rio de Janeiro, RJ – Brazil Atrial Fibrillation; Anticoagulants; Brain Ischemia; Vitamin K; Thromboembolism/ prevention and control. Keywords