**Preface to "Stroke, Dementia and Atrial Fibrillation"**

Stroke and dementia are among the top ten causes of death worldwide, as estimated by the World Health Organization. Atrial fibrillation (AF) is estimated to cause about 15% of all ischemic strokes and as much as 30% of strokes occurring in people in their 80s. The reduction of the burden of stroke related to AF is a difficult goal to achieve due to several clinical characteristics of AF itself: (1) Episodes of arrhythmias may be asymptomatic and misdiagnosed. (2) Stroke related to AF tends to be recurrent if an appropriate treatment is not promptly initiated. (3) During AF, silent ischemic stroke may occur that may not clinically manifest but may impact cognitive function. Indeed, silent ischemic cerebrovascular events have been recently proposed as the main pathophysiologic mechanisms linking AF with cognitive decline and dementia. (4) Finally, the disjunction between the risks of cerebrovascular events (CVE) and the burden of arrhythmias is held as a dominant concept in AF. Accordingly, the risk of CVE is not directly related to the presence of the arrhythmia but persists even during arrhythmia-free intervals. In other words, the two forms of AF classified according to duration (paroxysmal vs. persistent) of arrhythmias hold the same risk of stroke.

Given the complexity of this topic and its impact on clinical practice and public health, *Medicina* launched a Special Issue entitled "Stroke, Dementia and Atrial Fibrillation" with the aim of gathering together accurate and up-to-date scientific information on all aspects of association between cerebrovascular events, cognitive impairment and AF. The published articles not only report on the pathophysiological mechanisms underpinning this association, but also describe the results of latest clinical research about stroke prevention in AF and offer a comprehensive overview of the recent advances in understanding pharmacological interventions to prevent CVE.

> **Vincenzo Russo, Riccardo Proietti** *Editors*
