Pharmacological cardioversion of atrial fibrillation with vernakalant: evidence in support of the ESC Guidelines

Pharmacological rhythm control (often including electrical or pharmacological cardioversion) is an integral part of therapy for atrial fibrillation (AF) worldwide. Antiarrhythmic drug strategies would be preferred in many patients provided effective and safe antiarrhythmic agents are available. Also, pharmacological cardioversion could be the preferred option if the limitations of currently available drugs, such as restriction to patients without structural heart disease (flecainide and propafenone), risk of torsade de pointes (ibutilide), and slow onset of action (amiodarone), were overcome. The intravenous formulation of vernakalant (Brinavess, Cardiome) has been approved for pharmacological cardioversion of recent-onset AF (≤7 days) and early (≤3 days) post-operative AF in the European Union, Iceland, and Norway. Vernakalant has a high affinity to ion channels specifically involved in repolarization of atrial tissue and has minimal effects in the ventricles and thus, is thought to have a low proarrhythmic potential. Vernakalant is administered as a 10 min infusion of 3 mg/kg, and if AF persists after 15 min, an additional dose of 2 mg/kg can be given. The efficacy and safety of the drug has been extensively investigated in randomized controlled trials against placebo and an active comparator (amiodarone). The placebo-extracted efficacy of vernakalant is ∼47%. A significant advantage is a rapid effect, with the median to conversion ranging between 8 and 14 min, with the majority of patients (75-82%) converting after the first dose. Vernakalant retained its efficacy in subgroups of patients with associated cardiovascular disease such as hypertension and ischaemic heart disease, but its benefit may be lower and risk of adverse effects is higher in patients with heart failure. In the post-market reports, cardioversion rates with vernakalant are 65-70%. This review focuses on the role of vernakalant in pharmacological cardioversion for AF.