Stroke and atrial fibrillation: where to go from here?

S troke and atrial fibrillation (AF) are both frequent diseases (with respective prevalence >2.5% and >1% of the adult population in developed countries) and have major medical and financial impact. The link between the 2 diseases has been long since identified; the presence of AF is independently associated with a raw 5-fold increased risk of stroke. 1 Cardiologists have learned from the Atrial Fibrillation Follow-up Investigation of sinus Rhythm Management (AFFIRM) studies that conventional medical practice could not decrease mortality in AF. 2 More specifically, the antiar-rhythmic drugs are associated with increased mortality, and only warfarin (ie, preventing stroke) is associated with a positive impact on the mortality. 2 It was also suggested that the benefit of maintaining sinus rhythm could have been counterbalanced by stopping warfarin in patients in sinus rhythm. 3 Accordingly, updated guidelines have better emphasized the importance of preventing stroke in AF management. 4–6 Revised stroke risk stratification tools are now routinely used by clini-cians for the management of AF patients. And the practice has actually changed during the past years. Rationalized indication for anticoagulant prescription together with the availability of direct oral anticoagulant lets hope for a better risk-benefit balance in the prevention of embolic risk associated with AF. However, to initiate appropriate treatment, the physicians must first detect the AF and both the primary and the secondary prevention of AF-related stroke remain challenging when AF episodes have not been diagnosed. Under detection of AF episodes frequently occurs when AF is sporadic (parox-ysmal AF) or when asymptomatic (referred to as silent AF). Silent AF episodes have been reported in up to one third of AF patients. 4 After cryptogenic ischemic stroke, the use of enhanced ECG monitoring techniques including implanted devices provides rates of newly detected AF up to >10% of patients. It is tempting to speculate that these AF episodes might be causative of ischemic stroke. Indeed, relatively short episodes of atrial arrhythmias, around a few minutes, are actually associated with an increased risk of thromboembolism. As of today, it is not yet clear what are the key ECG characteristics of atrial arrhythmias that might be associated with thrombus formation and stroke and therefore who may warrant antithrombotic therapy. One of those missing key data is the duration of the arrhythmia episodes. In the current issue of Stroke, Arsava et al 12 report the findings from a retrospective study conducted in a cohort of …