Study objectives: We determine the risk for stroke of patients with atrial fibrillation in the emergency department (ED) and analyze the use of stroke prophylaxis in this setting.
Methods: This was a cross-sectional study carried out in 12 EDs. Clinical variables, risk factors for stroke, the prophylaxis prescribed, and the reasons for not initiating anticoagulation were collected. Risk factors and indications for therapy were evaluated according to the American College of Chest Physicians' 1998 recommendations.
Results: Of 1,178 patients included, 69% were not taking anticoagulants. Of the latter, 89% patients had indications for anticoagulation (age >75 years 59%, hypertension 56%, cardiac disorders 29%, heart failure 22%, diabetes 22%, previous embolism 14%), and 63% of the patients had 2 or more risk factors. Anticoagulation was prescribed in the ED to 27% of patients (67% with warfarin, 33% low-weight heparin plus warfarin), antiplatelets to 20% of patients, and no thromboprophylaxis to 53% of these eligible patients. Anticoagulants were prescribed in only 9% of patients with risk factors and current prophylaxis with antiplatelet agents. The main reasons for not prescribing anticoagulation in the presence of risk factors were advanced age (11%), contraindication for anticoagulation (27%), or because it was not considered to be indicated by the physicians (23%).
Conclusion: Most patients seen in the ED with atrial fibrillation are at high risk of stroke. Despite this risk, anticoagulation is underused in this setting, mainly because of the influence of advanced age on medical decisions and the reluctance to change current antiplatelet therapy.