Amiodarone Reduction After VT Ablation
Can amiodarone be safely reduced or discontinued following ablation of ventricular tachycardia (VT) in patients with structural heart disease?
Consecutive patients with structural heart disease undergoing VT ablation were divided into three groups by amiodarone use: group A) amiodarone reduced or discontinued following ablation, group B) amiodarone not reduced, group C) not on amiodarone at the time of ablation. Baseline characteristics and outcomes were compared.
A total of 231 patients (90% male, mean age 63 years, 54% ischemic cardiomyopathy) were included. The rate of amiodarone use in patients presenting for VT ablation was about 55% (n = 128). Following ablation, amiodarone was either decreased or discontinued in 43% of those patients (n = 99), and increased or continued without change in 13% (n = 29). 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 performed within a few days of ablation. In follow-up, 1-year VT-free survival was similar between groups (p = 0.1). Mortality was highest in group B (p < 0.001). Higher amiodarone dose after ablation (hazard ratio, 1.23; 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 or discontinued.
The authors stopped amiodarone 2 weeks before scheduled VT ablation “when possible,” although they do not specify their criteria to do so or, as far as I can tell, in how many patients this was possible. Even with a 2-week washout, the levels of amiodarone are significant, especially if patients had been on the medication chronically. In addition to its retrospective nature, the complexity of amiodarone pharmacokinetics and the pooling of patients whose amiodarone was either discontinued or reduced make this study hypothesis generating, rather than definitive. However, given that VT noninducibility post-ablation has been associated with improved event-free survival, and that amiodarone is associated with an increased risk of noncardiac side effects and mortality in some heart failure patients, this thought-provoking paper underscores the need for a prospective randomized trial of amiodarone discontinuation versus continuation in patients who are noninducible after ablation.
Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure
Keywords: Arrhythmias, Cardiac, Amiodarone, Anti-Arrhythmia Agents, Cardiomyopathies, Catheter Ablation, Disease-Free Survival, Heart Failure, Pharmacokinetics, Tachycardia, Ventricular
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