Long-term efficacy of empirical chronic amiodarone therapy in patients with sustained ventricular tachyarrhythmia and structural heart disease

The efficacy of empirical chronic oral amiodarone therapy in 129 patients with sustained ventricular tachyarrhythmia (VT/VF) and structural heart disease is evaluated. Twenty-nine patients were treated with class I drugs and monitored by electrophysiological study (EPS) and Holter electrocardiogram (ECG) (class 1). The remaining 100 non-responders to the class I drugs were treated with oral amiodarone, of whom 70 were tolerant (AMD(+)) and 30 were intolerant (AMD(-)). Patients were followed up to 36 months. The primary and secondary end-points were recurrence of VT/VF and hypothetical death, respectively; whereby, hypothetical death was defined as actual death and the event of rapid VT/VF (heart rate >240 beats/min) in patients with an implantable cardioverter defibrillator. Class I and AMD+ patients showed a better prognosis than AMD(-) patients. The VT/VF event free at 36 months in class 1 (64.8%) and AMD(+) (56.1%) patients were significantly higher than that in AMD- (27.2%) (p<0.01) patients. Hypothetical survival rates in class I (92.0%) and AMD+ (83.6%) patients were significantly higher than that in AMD- (57.0%) (p<0.001) patients, but there were no significant differences in the actual survival rate among the 3 patient groups. The independent clinical factors suppressing the recurrence of VT/VF (Cox hazard) were treatment with amiodarone (p=0.02, 95 % confidence interval (CI) =0.19-0.86) and EPS/Holter ECG-guided Class I drugs (p=0.04, 95% CI=0.14-0.94). The results demonstrate that empirical amiodarone has a substantial long-term benefit that is comparable to EPS/Holter ECG-guided class I drugs in the treatment of high-risk patients with VT/VF and structural heart disease.