Comparing the Imperfect With the Imperfect

Atrial fibrillation (AF) is the most common arrhythmia in the United States, with ≈7 million Americans estimated to have AF by 2020.1,2 A major cause of morbidity and mortality in AF is stroke. Pharmacological therapy for the prevention of stroke has undergone a renaissance with the advent of newer oral anticoagulants that are safe and effective alternatives to warfarin. However, the decision to initiate anticoagulation remains a subjective assessment of risks versus benefits. Although guided by well-validated risk scores for stroke and bleeding,3–5 real-world decisions on anticoagulation continue to differ significantly from guideline recommendations, with many patients at high risk not receiving anticoagulation because of a perceived high risk of bleeding and many low-risk patients being anticoagulated as a result of a perceived low risk of bleeding, the so-called risk-treatment paradox.6 This phenomenon, thought to account for the continued underuse of oral anticoagulation therapy,7 has yet to be validated in a large outpatient-based practice. Therefore, the present study by Steinberg et al8 in this issue of Circulation is a timely effort to better understand and address some of the reasons underlying this risk mismatch in thromboembolic assessment and anticoagulation therapy in a community outpatient-based group of patients with stable AF.Article see p 2005The authors examined 10 094 AF patients enrolled in the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) between June 2010 and August 2011.9 This US prospective registry of incident and prevalent AF is formed by a multispecialty collaboration of healthcare providers, including primary care physicians, cardiologists, and electrophysiologists. It is the largest clinical registry of its kind in the United States, enrolling ≈10 000 patients from 200 US outpatient practices. The patients are followed up for at least 2 years to characterize real-world …