Characterization of patients with atrial fibrillation not treated with oral anticoagulants

Objective. An underuse of oral anticoagulants (OAC) in patients with atrial fibrillation (AF) has been suggested, as only 50% of all patients with AF receive OAC treatment. Whether this is due to contraindications, lack of an indication to treat, or an expression of underuse is sparsely investigated. This study therefore aimed to characterize individuals without OAC treatment in a real-life population of patients with AF. Design. Retrospective cross-sectional study. The medical records were scrutinized in order to identify the type of AF, risk factors for embolism and bleeding, and other factors of importance for OAC treatment. Setting. The municipalities of Skellefteå and Norsjö, northern Sweden. Subjects. A total of 2274 living residents with at least one verified episode of AF on or before December 31, 2010. Main outcome measures. Prevalence of treatment with OAC and documented reasons to withhold OAC treatment. Results. Among all 2274 patients with AF, 1187 (52%) were not treated with OAC. Of the untreated patients, 19% had no indication or had declined or had experienced adverse effects other than bleeding on warfarin treatment. The most common reason to withhold OAC was presence of risk factors for bleeding, found in 38% of all untreated patients. Furthermore, a documented reason could be identified to withhold OAC in 75%. Conclusions. Among patients with AF without OAC treatment a reason could be identified to withhold OAC in 75%. The underuse of OAC is estimated to be 25%.