Role of amiodarone in heart failure

Amiodarone is a unique drug with potential benefits in heart failure. Unlike other antiarrhythmic drugs, amiodarone has properties of all four of the Vaughan-Williams classes. Amiodarone causes hemodynamic effects, as a result of its direct effect on smooth muscle and its calcium channel and alpha adrenergic blockade; it dilates coronary arteries and increases coronary blood flow. Amiodarone also causes peripheral arterial vasodilatation and decreases systemic blood pressure and afterload. There have been several clinical trials that demonstrated the beneficial effects of amiodarone therapy in heart failure involving small number of patients. The effect of amiodarone on survival in patients with CHF was recently examined in two large randomized, placebo-controlled trials. The Gruppo de Estudo de la Sobrevida en la Insufficiencia Cardiaca en Argentina (GESICA) was performed in Argentina, and the Survival Trial of Antiarrythmic Therapy in Congestive Heart Failure (CHF-STAT) was performed in Veterans' Administration hospitals in the United States. The results of the GESICA trial suggested that the addition of amiodarone improved survival, decreased hospital admissions for congestive heart failure, and improved functional class in patients with heart failure. The CHF-STAT study demonstrated that amiodarone therapy was associated with no survival benefit for sudden death, despite significant suppression of ventricular arrhythmias and improvement in left ventricular function. In conclusion amiodarone is an effective antiarrhythmic agent in patients with heart failure. It has been shown to suppress ventricular ectopy with an acceptable frequency of adverse effects when administered in lower doses. The role of amiodarone in patients with ischemic cardiomyopathy and heart failure needs further study.