Intravenous vernakalant for acute termination of recent-onset atrial fibrillation in the emergency department.

BACKGROUND

Early conversion of recent-onset atrial fibrillation (AF) is of clinical value. Vernakalant is an atrial-selective, rapid-acting antiarrhythmic drug. We report a large cohort of consecutive patients receiving vernakalant for the conversion of AF and review the clinical trials reporting on its safety and efficacy.

OBJECTIVE

This study aimed to determine the effectiveness and safety of cardioversion of recent-onset AF with intravenous vernakalant in the emergency department.

METHODS

Retrospective observational study of adults presenting with recent-onset AF (≤48 hours) treated with intravenous vernakalant. Patients received either a simplified fixed-dose protocol (300 mg ± second dose of 200 mg) or a weight-adjusted protocol (3 mg/kg ± 2 mg/kg). The primary efficacy end point was conversion to sinus rhythm. Safety end points included all adverse events (AEs).

RESULTS

Among 328 consecutive patients treated with vernakalant (median age 61 years; 56% male), vernakalant restored sinus rhythm within minutes of administration in 268 patients (82%). First-dose conversion occurred in 68% (70% of the fixed-dose group vs 56% of the weight-adjusted-dose group; P = .015). Within a 48-hour time window, a shorter time from symptoms to treatment had a relatively low predictive ability (area under the receiver operating characteristic curve 0.61) for predicting cardioversion. AEs occurred in 34 patients (10%) but were almost invariably mild; serious AEs occurred in only 1 patient (0.3%) but involved a fatality attributable to unrecognized severe cardiomyopathy.

CONCLUSION

In an emergency department, intravenous vernakalant was highly effective for terminating recent-onset AF, rapidly converting 82% of AF episodes within minutes of drug administration.