Empiric Amiodarone versus “Ineffective” Drug Therapy in Patients with Refractory Ventricular Tachyarrhythmias

Abstract

Because of its presumed unique efficacy, amiodarone (AM) is often used to treat patients whose sustained ventricular tachyarrhythmias (VT/VF) appear to be drug-refractory. To examine the efficacy of AM in such patients, we performed a retrospective analysis of 77 patients with drug-refractory VT/VF treated with either empiric AM or with drugs predicted during electrophysiological (EP) testing to be ineffective (ID). To qualify for the study, patients had to have spontaneous, symptomatic VT/VF, and persistently inducible VT during serial EP testing with drugs. All 77 patients were offered therapy with AM. Those who refused were treated with ID, whenever possible, an ID was selected which "improved" the EP study compared to baseline. Originally, 68 patients elected AM and nine elected ID. Because of drug intolerance or inefficacy, 10 patients crossed over during the course of the study; a total of 71 patients were followed on AM for 15.7 +/- 11.0 months, and 16 on ID for 17.8 +/- 10.8 months (mean +/- SD). During follow-up, the cumulative recurrence of VT/VF at 6, 12, and 24 months for AM versus ID was 16 +/- 5% versus 44 + 12% (P less than 0.002), 32 +/- 6% versus 44 +/- 12% (NS), and 41 +/- 7% versus 44 +/- 12% (NS) (+/- SE). The recurrence of VT was significantly lower in the AM group only for the first 6 months of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)