Background and importance Flecainide is commonly used for conversion of recent onset (<48 hours) atrial fibrillation (AF) in haemodynamically stable patients attending the emergency department (ED). Vernakalant is a relatively new antiarrhythmic drug that showed efficacy and safety compared with placebo and amiodarone in clinical trials but few data are available regarding its effectiveness compared with oral flecainide.

Aim and objectives To evaluate successful cardioversion in patients treated with vernakalant or oral flecainide with recent onset AF attending the ED.

Material and methods A single centre, non-randomised, retrospective study was conducted in patients diagnosed with recent onset AF in the ED. Vernakalant was approved by the Pharmacy and Therapeutics Committee in June 2018. The flecainide group included patients who attended the ED from January to June 2018 and the vernakalant group from July 2018 to October 2020. Patients received intravenous vernakalant (3 mg/kg followed by 2 mg/kg if necessary) or oral flecainide (200–300 mg). Sociodemographic and clinical variables were obtained from electronic health records. The primary endpoint was percentage of patients that achieved sinus rhythm in the ED. Secondary outcomes were conversion time to sinus rhythm, length of stay in the ED and percentage of patients that maintained sinus rhythm after 3 months of cardioversion.

Results 63 patients were included in the study; 20 received vernakalant and 43 flecainide. Median age was 59 years (IQR 53–66) and 63% were men. Baseline characteristics were similar in both groups. Cardioversion was successful in 80% of patients treated with vernakalant and in 64.3% treated with flecainide (p=0.21). Conversion time was 13 min in the vernakalant group versus 489 min in the flecainide group (p<0.001). Patients treated with vernakalant were discharged earlier from the ED compared with those treated with flecainide (9 vs 20 hours, respectively; p=0.0061). The percentage of patients who maintained sinus rhythm after 3 months was 92% in both groups (p=0.97). One patient in each group experienced a mild adverse event (itching at the injection site with vernakalant and temporary hypotension with flecainide).

Conclusion and relevance Vernakalant achieved a higher cardioversion rate than oral flecainide in recent onset AF patients. Conversion was significantly faster and was associated with shorter hospital stay. However, long term effectiveness was similar between both drugs, as well as the safety profile.

Conflict of interest No conflict of interest