Stroke prevention in Atrial Fibrillation

Prof. Gregory Lip discusses how to keep the decision-making process for choosing an oral anticoagulant simple and practical   Stroke prevention is the cornerstone of the management of atrial fibrillation (AF), and effective stroke prevention means oral anticoagulation (OAC), irrespective of symptoms or whether a rate or rhythm control approach is employed.1 Whilst the Vitamin K antagonists (VKA, e.g. warfarin) remains widely used worldwide, the landscape of stroke prevention has changed markedly in recent years, with the availability of the non-Vitamin K antagonist oral anticoagulants, the novel oral anticoagulants (NOACs), with increasing ‘real world’ data supporting their use in everyday clinical practice.2–4 Whilst stroke risk is increased five-fold in AF, this risk is not homogeneous and is driven by the presence of various stroke risk factors.5 The more commonly encountered risk factors have been used to formulate stroke risk stratification scores, such as the CHA2DS2-VASc score.6 The latter was designed to be simple, extending the older CHADS2 score by recognizing that age is an important driver of stroke risk (with the risk increasing above 65 years of age, although in Asians, this risk may rise from age 50 upwards, hence requiring a recalibration of the CHA2DS2-VASc score7,8), and that other commonly encountered risk factors such as ‘complicated’ vascular disease (e.g. myocardial infarction, peripheral artery disease) would also increase risks. Female sex is more a ‘risk modifier’ rather than a risk factor per se , since there is an age dependency to this risk—and the stroke risk is low and not accentuated in females age <65 or if no other risk factors are present.1 Much more complicated clinical risk scores with numerous clinical and/or laboratory parameters have been proposed, with …