815 Predictors of 90-Day Death Following an Emergency Department Visit for Atrial Fibrillation

Almost 10% of patients seen in the emergency department for atrial fibrillation die within a year of the visit. We sought to assess predictors of mortality in a real-world, older population of atrial fibrillation patients who were discharged from the emergency department, and to determine care strategies associated with mortality. We performed a retrospective cohort analysis of all patients age ≥ 65 with a primary emergency department diagnosis of atrial fibrillation, seen in all non-paediatric emergency departments in the province of Ontario, Canada between April 2007 and March 2010. Patients admitted to hospital were excluded, and only the index (first) emergency department visit was assessed. We evaluated the effect of post-discharge outpatient care and medications, emergency department cardioversion, and site volumes of atrial fibrillation patients on the adjusted hazard of death within 90 days of the index visit. Patients were censored on return to an emergency department. Among 12,772 qualifying index emergency department visits, there were 417 (3.3%; 95% CI 3.0% to 3.6%) deaths within 90 days of the visit. Patients with no follow-up care had an increased hazard of death (HR 2.27, p<0.001), relative to those who saw a family doctor, as did patients prescribed a calcium-channel blocker (HR 1.55, p=0.004), relative to a beta-blocker. A filled warfarin prescription was associated with a lower hazard of death (HR 0.70, p=0.02). Neither site volumes of atrial fibrillation patients (HR 0.66; p=0.10) nor cardioversion (HR 0.69; p=0.15) were associated with 90-day mortality. Among older atrial fibrillation patients seen in and discharged from the emergency department in the province of Ontario, lack of follow-up care had the greatest association with subsequent mortality. If more of these patients are to be discharged from emergency departments in future, the focus must go beyond emergency department care itself, to ensuring ongoing care subsequent to the emergency visit.