A Randomized Active-Controlled Study Comparing the Efficacy and Safety of Vernakalant to Amiodarone in Recent-Onset Atrial Fibrillation

Study Questions:

Is vernakalant more effective than amiodarone for acute conversion of atrial fibrillation (AF)?


Two hundred and thirty-two patients (mean age 63 years) with AF lasting 3-48 hours in duration were randomly assigned to one of two intravenous therapies: vernakalant, 3 mg/kg over 10 minutes, then an additional 10-minute infusion of 2 mg/kg if necessary 15 minutes later (n = 116); amiodarone 5 mg/kg over 60 minutes, then 50 mg over an additional 60 minutes (n = 116). The study was double-blinded. The primary endpoint was conversion to sinus rhythm (SR) within 90 minutes of first exposure to the study drug.


Conversion to SR occurred significantly more often in the vernakalant group (51.7%) than in the amiodarone group (5.2%). The mean time to conversion was 11 minutes with vernakalant. The study drug was discontinued because of a serious adverse event in 2.6% of patients in the vernakalant group compared to 0.9% in the amiodarone group. Torsades de pointes, ventricular fibrillation, polymorphic ventricular tachycardia (VT), or sustained monomorphic VT did not occur in either group.


Vernakalant is approximately 10 times more effective than amiodarone for the acute conversion of AF, and is well tolerated.


Vernakalant, an investigational agent in the United States, is a multiple ion channel blocker and is novel in that it blocks potassium channels that are present in the atrium and not in the ventricle (e.g., the ultra-rapid delayed rectifier current and the inwardly rectifying, acetylcholine-regulated current). The advantage of its atrial-selective action is a major reduction in the risk of ventricular proarrhythmia associated with other potassium-channel blockers such as ibutilide.

Clinical Topics: Diabetes and Cardiometabolic Disease, Dyslipidemia, Heart Failure and Cardiomyopathies, Prevention, Vascular Medicine, Atherosclerotic Disease (CAD/PAD), Lipid Metabolism, Nonstatins, Novel Agents, Statins, Acute Heart Failure, Chronic Heart Failure

Keywords: Stroke, Myocardial Infarction, National Heart, Lung, and Blood Institute (U.S.), Risk Reduction Behavior, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Risk Factors, Peripheral Arterial Disease, Heart Failure, Systolic, Primary Prevention, Lipoproteins, LDL, Renal Dialysis, Dyslipidemias, Lipoproteins, HDL, Risk Assessment

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