Additional Risk Factors for Stroke in Patients With AF In addition to consideration of bleeding risk and patient values and preferences, for patients with a CHADS2 score of 0 or 1, clinicians may wish to consider additional stroke risk factors when indi- vidualizing decisions about antithrombotic therapy. For instance, there is high-quality evidence that stroke risk increases continuously with age (rather than as a dichotomous function of age ,75 or 75 years) and moderate-quality evidence that female sex is an independent predictor of stroke risk in patients with AF.18,20 Thus, patients may be inclined to choose the more aggressive treatment option (eg, antithrom- botic therapy rather than no therapy for patients with a CHADS2 score of 0 and oral anticoagulation rather than aspirin for patients with a CHADS2 score of 1) when these additional risk factors for stroke are present. The presence of multiple non-CHADS2 risk factors for stroke may favor oral anticoagulation therapy. There is less-consistent evidence support- ing an independent association between vascular disease (ie, prior MI, complex aortic plaque seen on TEE, and peripheral arterial disease) and the risk of stroke in patients with AF (section 1.4.2).21-23 2.1.13 Percutaneous Closure of the Left Atrial Appendage: Percutaneous closure of the left atrial appendage (LAA) has recently been evaluated as a nondrug alternative for stroke prevention in patients with AF. The PROTECT-AF (WATCHMAN Left similar to the 33% relative reduction in stroke achieved with dabigatran 150 mg bid compared with VKA therapy (Table 9).84 Therefore, any advan- tages of dabigatran with respect to thromboembo- lism would likely not exist for motivated patients who are able to participate in home monitoring of their VKA therapy. 