First, congestive heart failure is not a consis- tently demonstrated independent predictor of stroke. Second, the risk associated with a history of hypertension may differ among patients with well-treated vs poorly treated hypertension.46-48 Third, in most studies, the CHADS2 score has only a modest ability to predict stroke in patients with AF (C statistic, 0.56-0.70).24,32,35-46 Finally, the threshold of stroke risk at which treatment with oral anticoagulation will be preferred is likely to decrease with the emergence of new oral anticoagulants that do not require reg- ular monitoring of the international normalized ratio (INR) and that may be associated with greater reductions in stroke and less risk of bleeding compared with adjusted-dose VKA therapy.49 Thus, stroke risk strati cation schema will need to evolve to more accurately identify patients who are at suf ciently low risk of stroke and can be treated with aspirin or no antithrombotic ther- apy, whereas all other patients with AF can be considered for oral anticoagulation. The CHA2DS2-VASc (congestive heart failure [or left ventric- ular systolic dysfunction], hypertension, age ,75 years; diabetes mellitus, prior stroke or transient ischemic attack, vascular disease, age 65 to 74 years, female sex) score is a new risk scheme that combines the CHADS2 score with additional moderate risk fac- tors, which were also included in the 2006 American College of Cardiology/American Heart Association/European Society of Cardiology and National Institute for Health and Clinical Excel- lence AF practice guidelines.29,50 Speci cally, the CHA2DS2-VASc score assigns points as in the original CHADS2 score (Table 2) with the exception of age 75 years, which is assigned two points. 