Comparing the efficacy and safety of sotalol and dofetilide for maintenance of normal sinus rhythm at a community health system Abigail Millsaps, Caitlin Casper, Dustin Bivins Northeast Georgia Medical Center – Gainesville, GA Background: Atrial fibrillation (AF) occurs when inappropriate electrical currents cause the atria to beat out of sync with the ventricles, creating the hallmark irregularly irregular heart rhythm. The risk of developing AF increases with age and structural heart damage, making AF a significant cause of morbidity and mortality worldwide. AF, if left untreated, can lead to cardiomyopathy, heart failure, and thromboembolism.
Sotalol and dofetilide are class III antiarrhythmic drugs used for pharmacologic cardioversion to normal sinus rhythm (NSR) in patients who have atrial fibrillation (AF) or atrial flutter. These agents act on potassium-gated channels in myocardial cells to delay repolarization, prolong the action potential duration, and increase the effective refractory period (ERP). An increase in ERP extends the amount of time that the myocyte cannot be stimulated to fire another action potential, thus leading to a decrease in the incidence of arrhythmogenicity. However, this mechanism of action increases the risk of excessive QT (QTc) prolongation, which can result in torsades de pointes (TdP) or significant ventricular arrhythmias. Therefore, manufacturer labeling and treatment guidelines recommend initiating these medications in a hospital setting with continuous cardiac monitoring.
There is only one randomized controlled trial directly comparing sotalol and dofetilide. The EMERALD trial, conducted in 1999, compared the safety and efficacy of dofetilide and sotalol to placebo for initial cardioversion from AF to NSR and found 29.5% of patients given dofetilide and 5.9% given sotalol converted into NSR without needing direct current cardioversion (DCCV). Researchers also found 71% of patients who converted to NSR and received dofetilide maintained NSR at 6 months compared to 59% who received sotalol. Researchers reported three cases of TdP, all in the dofetilide group.
Purpose: The purpose of this study was to determine if sotalol or dofetilide is more efficacious at maintaining NSR at 6 months post-cardioversion in patients with AF/a-flutter.
Methods: This was a retrospective chart review to determine the percentage of patients in NSR six months post-cardioversion either pharmacologically or via DCCV after being loaded inpatient with dofetilide or sotalol. The study population included adults ≥18 years old at Northeast Georgia Health System (NGHS) between to January 1, 2022 to August 31, 2025 who were hospitalized with AF or a-flutter, completed inpatient loading with sotalol or dofetilide, achieved NSR prior to discharge either pharmacologically or via DCCV, and were continued on the selected treatment at discharge. Patients were excluded if they had a historical use of dofetilide or sotalol, concurrent use of other antiarrhythmic medications, baseline contraindications, documented non-adherence to study medications, history of ventricular arrhythmias, or were part of a vulnerable population. Authors used chi-squared analysis to evaluate primary and secondary endpoints.
Results: Between January 1, 2022 and August 31, 2025, 57 of 335 patients on sotalol and 17 of 53 patients on dofetilide met inclusion criteria. Baseline characteristics were similar between groups. We found no statistically significant difference in normal sinus rhythm at 6-months between sotalol and dofetilide (84.2% vs 82.4%; p = 0.557). There were no statistically significant differences in incidence of TdP or the percentage of patients requiring DCCV prior to discharge (76.5% vs 91.2%; p = 0.116).
Conclusion: Based on these findings, there is no difference between sotalol and dofetilide at maintaining NSR at 6 -months. Only one occurrence of TdP was detected in the sotalol group, and the dofetilide group had a lower percentage of patients requiring DCCV before discharge; however, these were not statistically significant. Limitations of this study included its retrospective nature, small sample size, and reliance on provider documentation.
