Trends in anticoagulation for atrial fibrillation in the U.S.: an analysis of the national ambulatory medical care survey database.

OBJECTIVES: The purpose of this study was to track trends in the use of anticoagulation for atrial fibrillation (AF) over the past decade and identify predictors of use.
BACKGROUND: Atrial fibrillation is common and associated with significant morbidity. Previous studies suggest underuse of anticoagulant therapy in patients with AF.
METHODS: The National Ambulatory Medical Care Survey database was queried for all patient visits with a diagnosis of AF between 1994 and 2003. Other diagnoses, other medications, and demographic, visit, geographic, and provider characteristics were compared with the prescription of anticoagulation in predefined age and risk groups.
RESULTS: The prevalence of the diagnosis of AF and anticoagulation for AF has increased over the last decade. Increased age and use of rate control agents is associated with the use of anticoagulation. There is a trend toward less anticoagulation when a rhythm control agent is used instead of a rate control agent. Anticoagulation might be overused in a group of low-risk patients.
CONCLUSIONS: From 1995 through 2002, an increase has occurred in anticoagulation for AF, especially in those at highest risk for thromboembolic phenomena. A substantial number of patients at risk for thromboembolic events are not anticoagulated, and further studies are needed to determine how many of these patients are candidates for anticoagulation. Anticoagulation use has increased in nontargeted, low-risk groups in whom antiplatelet agents are appropriate. Use of a rhythm control agent might be associated with less use of anticoagulation.