Thirty-day and 1-year outcomes of emergency department patients with atrial fibrillation and no acute underlying medical cause.

STUDY OBJECTIVE: Atrial fibrillation is the most common dysrhythmia observed in the emergency department (ED), yet there is little research describing long-term outcomes after ED management. Our objective is to describe ED treatment approach, conversion success rates, ED adverse events, and 30-day and 1-year outcomes for a cohort of ED patients with atrial fibrillation and no acute underlying medical cause.

METHODS: This retrospective cohort study used a database from 2 urban EDs to identify consecutive patients with an ED discharge diagnosis of atrial fibrillation from April 1, 2006, to March 31, 2010. Comorbidities, rhythms, management, and immediate outcomes were obtained by manual chart review, and patients with an acute underlying medical condition were excluded by predefined criteria. Patients were stratified into 5 groups according to ED management: electrocardioversion, chemical cardioversion, spontaneous cardioversion, rate control only, and no arrhythmia-specific treatment. To identify deaths, strokes, and ED revisits within 1 year, each patient's unique provincial health number was linked to the provincial vital statistics registry and the regional ED database. Primary outcome was the number of patients having either stroke or death of any cause at 30 days, stratified by treatment group.

RESULTS: Of 927 consecutive eligible patients, 121 (13.1%) converted to sinus rhythm before ED intervention, 357 (38.5%) received ED rhythm control, and 449 (48.4%) did not receive rhythm control. Overall, 142 of 927 patients (15.3%) were admitted to the hospital at the index ED visit. At 30 days, 2 patients had a stroke and 5 died (combined outcome rate 0.8%; 95% confidence interval 0.3% to 1.6%). All 7 of these patients were admitted at the index ED visit.

CONCLUSION: In this large cohort of ED patients with atrial fibrillation and no acute underlying medical cause, the 30-day rate for stroke or death was less than 1%. Nearly 85% of patients-regardless of treatment approach or conversion to sinus rhythm-were discharged at the index ED visit, and none of these patients had a stroke or died at 30 days.