Differential Use of Warfarin for Secondary Stroke Prevention in Patients With Various Types of Atrial Fibrillation

Abstract

Anticoagulation therapy significantly reduces the incidence of thromboembolic events in patients with atrial fibrillation (AF), and warfarin therapy at discharge is a class I-indicated drug in patients with ischemic stroke with persistent or paroxysmal AF without contraindications. The aim was to determine whether participation in the Get With The Guidelines-Stroke (GWTG-S) quality improvement program would be associated with improved adherence to anticoagulation guidelines for patients with all types of AF. Adherence to warfarin treatment at hospital discharge was assessed in eligible patients with AF who presented with stroke or transient ischemic attack, based on type of AF. Of patients with stroke, 10.5% presented with some form of AF. When AF was documented using electrocardiography or telemetry (ECG) during the present admission, eligible patients were more likely to receive warfarin compared with patients for whom AF was reported using medical history only (78.8% vs 49.4%; p<0.0001). Improvement after GWTG-S participation in warfarin use was observed in patients with ECG-documented AF (73.8% at baseline vs 88.5% after the intervention; p<0.0001), but not patients using history only. Women and elderly patients were less likely to receive warfarin, and these gaps in treatment did not narrow during the quality improvement program for patients with ECG-documented AF and those with history only. In conclusion, anticoagulation for stroke prevention was underused in general for patients with AF, even in such high-risk groups as patients with stroke. GWTG-S was associated with improved adherence for patients with ECG-documented AF, but patients with a history of AF alone were largely untreated.