[Risk stratification and long-term therapy with amiodarone in patients with idiopathic dilated cardiomyopathy]

Patients with cardiomyopathy are known to suffer from a high prevalence of tachyarrhythmic complications and sudden cardiac death. In a prospective study, 30 patients (25 men, 5 women, mean age: 52 +/- 12 years) with dilated cardiomyopathy underwent 48-h-Holter monitoring and programmed electrical stimulation and, independent from the results of the diagnostic work-up, were then randomized either to amiodarone or to a conventional or no antiarrhythmic therapy. At baseline, frequent ventricular arrhythmias (> 30 ventricular premature beats/h) were observed in 15/30 patients (50%), 13 patients (43%) had repetitive ventricular arrhythmias, additionally. Four patients suffered spontaneous sustained tachyarrhythmias. During programmed electrical stimulation, sustained monomorphic ventricular tachycardia was induced in 3/3 patients with and in 1/25 patients (4%) without a history of sustained tachycardia. Sustained monomorphic ventricular tachycardia was induced with one to two extrastimuli; three extrastimuli only increased the incidence of inducible ventricular fibrillation (8 patients, 28%). During a mean follow-up of 28 +/- 6 months 10/30 patients (33%) died for cardiac reasons (sudden cardiac death: 4/10 patients). Cardiac death was most likely in patients with a left-ventricular ejection fraction < 35% (5/18 patients, 28% versus 1/12 patients with ejection fraction > 35%, 8%) and further increased in the presence of reduced exercise tolerance and frequent and repetitive ventricular arrhythmias (4/7 patients, 57%). In the amiodarone group 4/15 patients died (27%, sudden cardiac death: one patient), while in patients not treated by amiodarone 8/15 patients died (54%; sudden cardiac death: three patients). Amiodarone therapy was well tolerated in all but one patient.