Role of Antiarrhythmic Drug Therapy in Patients with Congestive Heart Failure

Abstract

The presence of arrhythmias in patients with congestive heart failure (CHF) is an independent risk factor for sudden death, and approximately 50% of deaths in patients with CHF can be characterized as sudden. The incidence of sudden arrhythmic death in patients with CHF is difficult to ascertain but is probably between 30% and 50% per year [1–3]. Therefore, reduction of the risk of sudden cardiac death in patients with CHF is a desirable clinical goal. Three reports have been made on the effects of antiarrhythmic drugs on mortality in patients with CHF. Chakko and Gheorghiade [1] described their uncontrolled retrospective experience with antiarrhythmic drugs in 43 patients and found no difference in outcome (Fig. 1). Subsequently, Parmley and Chatterjee [2] reported on a subgroup of patients with CHF, who were in studies originally designed to evaluate new inotropic drugs. Figure 2 demonstrates the differences in outcome depending on whether antiarrhythmic drugs were prescribed or not. This uncontrolled experience found lower mortality in those patients given quinidine, procainamide, or amiodarone and led the authors to call for a prospective and randomized trial to address the true value of antiarrhythmic drugs in such patients. Nicklas and his colleagues [3] at Michigan have reported in abstract form their experience in a prospective randomized evaluation of 100 patients treated with low dose amiodarone or placebo. Although this was a small study and lacked adequate power to detect any significant effect, there was no evidence of benefit from amiodarone (see Table 1).