Amiodarone Discontinuation or Dose Reduction Following Catheter Ablation for Ventricular Tachycardia in Structural Heart Disease.

Abstract

This study sought to examine long-term outcomes in patients with structural heart disease in whom amiodarone was reduced/discontinued after ventricular tachycardia (VT) ablation. VT in patients with structural heart disease increases morbidity and mortality. Amiodarone can decrease VT burden, but long-term use may result in organ toxicities and possibly increased mortality. Catheter ablation can also decrease VT burden. Whether amiodarone can be safely reduced/discontinued following ablation remains unknown. We studied consecutive patients undergoing VT ablation from 2008 to 2011, typically followed by noninvasive programmed stimulation several days later. Patients were divided into 3 groups by amiodarone use: group A-amiodarone reduced/discontinued following ablation; group B-amiodarone not reduced; group C-not on amiodarone at time of ablation. Baseline characteristics and outcomes were compared between groups. Overall, 231 patients (90% male; mean age: 63.4 ± 12.9 years; 53.7% ischemic cardiomyopathy) were included (group A: 99 patients; group B: 29 patients; group C: 103 patients). Group B patients were older with more advanced heart failure. Group A patients less frequently had inducible VT at the end of ablation or noninvasive programmed stimulation. In follow-up, 1-year VT-free survival was similar between groups (p= 0.10). Mortality was highest in group B (p< 0.001). Higher amiodarone dose after ablation (hazard ratio: 1.23; 95% confidence interval: 1.03 to 1.47; p= 0.02) was independently associated with shorter time to death. After successful VT ablation, as confirmed by noninducibility at the end of ablation and noninvasive programmed stimulation, amiodarone may be safely reduced/discontinued without an unacceptable increase in VTrecurrence. Reduction/discontinuation of amiodarone should be considered an important goal of VT ablation.