Vernakalant hydrochloride: A novel atrial-selective agent for the cardioversion of recent-onset atrial fibrillation in the emergency department.

OBJECTIVES: Vernakalant is a relatively atrial-selective antiarrhythmic agent that has been shown to successfully convert atrial fibrillation (AF) to normal sinus rhythm for some patients whose onset of dysrhythmia occurred less than 7 days previously. This study sought to evaluate the efficacy and safety of vernakalant for patients with recent-onset AF.

METHODS: This was a post hoc analysis of patients with recent-onset AF (> 3 to ≤ 48 hours) enrolled in the double-blind, placebo-controlled Atrial arrhythmia Conversion Trial (ACT) I and the open-label ACT IV trials. The studies enrolled adults presenting with AF to 78 emergency departments (ED) and cardiac clinics in six countries. Patients received a 10-minute intravenous infusion of vernakalant or placebo, followed by an additional infusion if necessary. Efficacy assessments included conversion to sinus rhythm within 90 minutes and median time to conversion. Safety evaluations included telemetry, Holter monitoring, and adverse events (AEs).

RESULTS: Of the 290 patients, 229 received vernakalant, 61 received placebo, and the overall mean age was 59 years. The vernakalant and placebo groups were similar. Of all patients given vernakalant, 136 (59.4%) converted to sinus rhythm within 90 minutes, compared with three (4.9%) placebo patients. The median time to conversion with vernakalant was 12 minutes (interquartile range = 7-24.5 minutes). Clinically significant bradycardia and hypotension were uncommon, and no cases of torsade de pointes or ventricular fibrillation occurred.

CONCLUSIONS: Vernakalant rapidly converted recent-onset AF to sinus rhythm in over half of patients, was well tolerated, and has the potential to offer an important therapeutic option for rhythm control of recent-onset AF in the ED.