Acute Cardioversion versus a Wait And See-approach for recent-onset symptomatic atrial fibrillation in the emergency department: Rationale and Design of the randomized ACWAS-trial

Abstract Background Current standard of care for patients with recent onset atrial fibrillation (AF) in the emergency department aims at urgent restoration of sinus rhythm, although paroxysmal AF is a condition that resolves spontaneously within 24 hours in over 70% of the cases. A wait-and-see approach with rate-control medication only and when needed cardioversion within 48 hours of onset of symptoms is hypothesized to be non-inferior, safe and cost-effective as compared to current standard of care and to lead to a higher quality of life. Design The ACWAS-trial ( NCT02248753 ) is an investigator-initiated, randomized, controlled, 2-arm non-inferiority trial which compares a wait-and-see approach to the standard of care. Consenting adults with recent onset symptomatic AF in the emergency department without urgent need for cardioversion are eligible for participation. A total of 437 patients will be randomized to either standard care (pharmacological or electrical cardioversion) or the wait-and-see approach, consisting of symptom reduction through rate control medication until spontaneous conversion is achieved, with the possibility of cardioversion within 48 hours after onset of symptoms. Primary endpoint is the presence of sinus rhythm on 12-leads electrocardiogram (ECG) at 4 weeks, main secondary outcomes are adverse events, total medical and societal costs, quality of life and cost-effectiveness during 1 year. Conclusions The ACWAS-trial aims at providing evidence for the use of a wait-and-see approach for patients with recent onset symptomatic AF in the emergency department.