The Improved but Unfinished Business of Stroke Risk Stratification in Atrial Fibrillation

Abstract

With an estimated lifetime risk of 1 in 4 men and women >40 years of age, atrial fibrillation (AF) is the most common arrhythmia worldwide and poses a significant burden of morbidity and mortality from stroke and thromboembolism (TE). As with other areas of cardiovascular medicine (eg, acute coronary syndromes), risk stratification schemes for AF aim to individualize risk prediction of disease to guide therapies for both primary and secondary prevention. Improved risk stratification schemes for AF will also enable clinicians to treat the patients at greatest risk of stroke and TE and avoid treatment in patients at negligible risk. Given that oral anticoagulation (OAC) is the most effective drug to prevent TE in AF, there is now a paradigm shift towards getting better at identifying ‘‘truly low risk’’ patients with AF who do not need any antithrombotic therapy whilst others with 1 stroke risk factors should be considered for OAC. The process of refinement and improvement of risk stratification requires validation and comparison of existing and new scores in different populations and different clinical scenarios. Although AF can be classified as paroxysmal, persistent, or permanent, guidelines suggest that patients with paroxysmal AF should be regarded as having a stroke risk similar to those with persistent or permanent AF, in the presence of risk factors. Patients aged 75 years, diabetes mellitus, and stroke (2 points). OAC therapy is currently indicated in patients with a CHADS2 score 2. However, the risk of stroke increases