Vernakalant versus procainamide for rapid cardioversion of patients with acute atrial fibrillation (RAFF4): randomised clinical trial

1. Vernakalant was superior to procainamide for rapid cardioversion of patients with acute atrial fibrillation, with a higher conversion rate and faster times to conversion.

Evidence Rating Level: 1 (Excellent)

Although procainamide is the most commonly used antiarrhythmic for acute atrial fibrillation in Canadian emergency departments, it has only moderate efficacy (50%), requires a slow infusion, and has a moderate rate of adverse events. The newer drug vernakalant may offer advantages such as a higher conversion rate, faster administration and onset, and fewer adverse events. This study thus compared the effectiveness and safety of intravenous vernakalant and intravenous procainamide for the management of acute atrial fibrillation in the emergency department. This randomised clinical trial included patients with acute atrial fibrillation from 12 tertiary care emergency departments in Canada. Patients were randomised 1:1 to either intravenous infusion (3 mg/kg over 10 minutes) of vernakalant or procainamide (15 mg/kg in 500 mL of normal saline given over 60 minutes (maximum dose 1500 mg)). Patients were offered electrical cardioversion when rapid conversion did not occur. The primary outcome was conversion to sinus rhythm within 30 minutes of completion of drug infusion. Among the 350 patients included in the study, 172 received procainamide (mean [SD] age = 62.4 [15.2] years, male [%] = 114 [66.3]) and 178 received vernakalant (mean [SD] age = 63.5 [15.0], male [%] = 108 [60.7]). Vernakalant was more effective than procainamide for the conversion to sinus rhythm within 30 minutes of infusion completion (62.4% vs 48.3%; adjusted absolute difference 15.0%, 95% confidence interval [CI] 4.6% to 25.0%; adjusted odds ratio [OR] 1.87, 95% CI 1.2 to 2.9). With vernakalant, time to conversion was faster than with procainamide (21.8 vs 44.7 minutes; mean difference −22.9, 95% CI −29.9 to −16.0), and fewer patients underwent attempted electrical cardioversion (33.7% vs 44.2%; OR 0.62, 95% CI 0.39 to 0.96). Adverse events were mild and brief, and similar in both groups. Overall, this study found vernakalant to be superior to procainamide for rapid cardioversion of patients with acute atrial fibrillation. These findings suggest vernakalant is a safe and effective intravenous alternative for the rapid cardioversion in this population. Future studies are needed to confirm these findings.

Click here to read this study in BMJ

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