Stratifying Stroke Risk in Atrial Fibrillation: Beyond Clinical Risk Scores.

Abstract

See releated articles, pp 2653, 2654, 2660, 2671 Atrial fibrillation (AF) is the most common atrial arrhythmia, affecting ≈1% of the US population.1 This estimate may understate its true burden, given that a high proportion of patients have subclinical AF. The prevalence of AF increases with age,1,2 and given an aging population, the projected prevalence of AF in the United States is at least 5.6 million by the year 2050.2 AF is associated with increased risk of stroke or systemic embolism3 and death.4 The heightened thromboembolic risk seen in AF is substantially reduced by anticoagulation.5 On the contrary, long-term anticoagulation can also lead to hemorrhagic complications. The recommended approach to making decisions about anticoagulant therapy in AF is to balance the expected risks of stroke versus bleeding. In this article, we review the widely used clinical methods for predicting stroke risk in AF and augment this discussion with an overview of more recent risk predictors beyond conventional clinical scores. ### Risk Factors Several studies have reported risk factors for stroke in patients with AF. A pooled analysis of 5 trials with 5956 patient-years of follow-up found that independent risk factors for ischemic stroke were age (relative risk [RR] per 10 years, 1.4), prior stroke or transient ischemic attack (TIA; RR, 2.5), hypertension (RR, 1.8), diabetes mellitus (RR, 1.7), and congestive heart failure (RR, 1.4).6 In patients 75 years of age with one or more of these risk factors, the annual stroke rate was 8.1% (95% CI, 4.7%–13.9%).6 Another systematic review, including 7 studies with >12 000 patients, identified the …