Cohn BG, Keim SM, Yearly DM. Is Emergency Department Cardioversion of Recent-Onset Atrial Fibrillation Safe and Effective? J Emerg Med. 2013 Apr 30.
The authors provide a review of five observational studies compiling a total of 1,593 ED patients with atrial fibrillation treated by either rate control or cardioversion. The clinical question asked by these authors was whether or not a particular subset of patients presenting to the ED with recent-onset (defined as onset less than 48 hours prior to presentation) AF or AFL for whom direct-current cardioversion (DCC) followed by discharge home is safe and effective. Previous studies have shown the risk of thromboembolic events among these patients to be as low as 0.8%. Potential benefits from DCC include decreased length of stay, decreased cost, and improved patient satisfaction.
Five articles were selected for review from a PubMed search specific to the topic of ED cardioversion for recent-onset AF. Of the cohort studies reviewed, two were retrospective and three were prospective. In total, eleven medical centers were included in these non-industry sponsored cohort studies ranging from Maine to Vancouver. Combining the five observational studies revealed 1,593 cases involving ED DCC. Overall, success rates ranged from 85.5% to 97%, with only one (0.06%) thromboembolic complication reported. The one observed stroke occurred within 48 hours of visiting the hospital in a patient who was not on anticoagulation post DCC.
Unfortunately, none of the studies compared complication rates to a control group of patients treated with alternative strategies. Furthermore, patient satisfaction rates of DCC were not adequately assessed and compared to alternative treatment regiments. Regarding cost effectiveness, only one article that was reviewed addressed the potential cost benefit for rapid cardioversion and found no significant cost difference. That said, additional studies are needed to determine if there is a potential for cost savings. Further research may also better assess patient satisfaction of DCC compared to alternative treatment regimens, and better identify patients at low risk for thromboembolic events. The authors of this review also bring up the question of whether the upper limit of new onset should be defined as less than 48 hours, or is there some other time point where failure rate begins to rise. Based on this review of five cohort studies regarding ED cardioversion of recent-onset AF or AFL, DCC should be offered as a safe and effective treatment with success rates ranging from 85.5-97% and risk of thromboembolic phenomena as low as 0.06%.