Stroke Prevention in Atrial Fibrillation: Focus on Latin America

Abstract

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, with an estimated prevalence of 1-2% in North America and Europe. The increased prevalence of AF in Latin America is associated with an ageing general population, along with poor control of key risk factors, including hypertension. As a result, stroke prevalence and associated mortality have increased dramatically in the region. Therefore, the need for effective anticoagulation strategies in Latin America is clear. The aim of this review is to provide a contemporary overview of anticoagulants for stroke prevention. The use of vitamin K antagonists (VKAs, eg, warfarin) and aspirin in the prevention of stroke in patients with AF in Latin America remains common, although around one fifth of all AF patients receive no anticoagulation. Warfarin use is complicated by a lack of access to effective monitoring services coupled with an unpredictable pharmacokinetic profile. The overuse of aspirin is associated with significant bleeding risks and reduced efficacy for stroke prevention in this patient group. The non-VKA oral anticoagulants (NOACbs) represent a potential means of overcoming many limitations associated with VKA and aspirin use, including a reduction in the need for monitoring and a reduced risk of hemorrhagic events. The ultimate decision of which anticoagulant drug to utilize in AF patients depends on a multitude of factors. More research is needed to appreciate the impact of these factors in the Latin American population and thereby reduce the burden of AF-associated stroke in this region.

Figure 1

Algorithm for anticoagulation in Latin American patients with atrial fibrillation. The decision to initiate anticoagulant therapy is based on the use the CHA ₂ DS ₂ VASc, HAS-BLED and SAMeTT2R2 scores through determination of stroke risk, bleeding risk and likelihood of warfarin success, respectively. INR: international normalised ratio; NOAC: non-vitamin K antagonist oral anticoagulants; NSAID: non-steroidal anti-inflammatory drug; TTR: time in therapeutic range; VKA: vitamin K antagonist. Adapted from (81).

Figure 2

Patient profiling in NOAC selection. The patient groups highlighted are likely to be of greatest importance to the Latin American context. Individual non-VKA oral anticoagulant (NOAC) use is based on non-inferiority to warfarin for stroke prevention in non-valvular atrial fibrillation and individual drug characteristics. Adapted from (81). VKA: vitamin K antagonist; GI: gastrointestinal.