Increasing rate of atrial fibrillation from 2003 to 2011 in patients with ischaemic stroke: results from 55 551 patients in a nationwide registry

BACKGROUND AND PURPOSE: The general awareness of atrial fibrillation is increasing. The key to prevent atrial fibrillation related stroke is oral anticoagulation therapy; however, it has often been proposed that oral anticoagulation therapy is under-utilized despite indication. The aim of the study was to examine the trends in atrial fibrillation rate in patients after acute ischaemic stroke and to determine whether the use of oral anticoagulation therapy increased from 2003 to 2011. METHODS: In the nationwide Danish Stroke Registry 55 551 patients (≥18 years) admitted with acute ischaemic stroke were identified. Frequency analysis and linear regression were used to assess trends in atrial fibrillation diagnosis and oral anticoagulation therapy prescription. RESULTS: A total of 17.1% (n = 9482) of ischaemic stroke patients had atrial fibrillation. The relative frequency of atrial fibrillation increased significantly during the study period (16.3%-20.1%). The prescription rate of oral anticoagulation therapy had a yearly increase five times higher than the atrial fibrillation rate. CONCLUSION: From 2003 to 2011 atrial fibrillation detection rate increased significantly, which was followed by a more marked increase in the use of oral anticoagulation therapy, most probably reflecting an increased awareness and questioning assumed current under-use of oral anticoagulation therapy in secondary stroke prevention.