Elsevier

Heart Rhythm

Volume 13, Issue 7, July 2016, Pages 1552-1559
Heart Rhythm

CONTEMPORARY REVIEW
Comparative effectiveness of antiarrhythmic drugs and catheter ablation for the prevention of recurrent ventricular tachycardia in patients with implantable cardioverter-defibrillators: A systematic review and meta-analysis of randomized controlled trials

https://doi.org/10.1016/j.hrthm.2016.03.004Get rights and content

Background

Treatment strategies to prevent ventricular tachycardia (VT) in patients with an implantable cardioverter-defibrillator (ICD) include antiarrhythmic drugs (AADs) and catheter ablation (CA).

Objective

The purpose of this study was to systematically compare the efficacy of AADs and CA for the prevention of VT in patients with ICDs.

Methods

Major databases were searched (October 2015) for randomized trials evaluating AADs or CA vs standard medical therapy to prevent VT in ICD patients. Primary outcome was the number of VT episodes leading to appropriate ICD interventions.

Results

Eight trials (n = 2268, follow-up 15 ± 6 months) evaluated AADs, and 6 trials (n = 427, follow-up 14 ± 8 months) evaluated CA. A significant reduction in appropriate ICD interventions was found with both CA (odds ratio [OR] 0.45, 95% confidence interval [CI] 0.28–0.71, P = .001) and AADs (OR 0.66, 95% CI 0.44–0.97, P = .037), with no significant difference between the 2 treatment strategies. The benefit of AADs was driven by amiodarone and not confirmed with other AADs. A reduction of inappropriate ICD interventions was found with AADs (OR 0.30, P = .001) but not with CA. Both CA and AADs were not associated with decreased mortality over follow-up. Amiodarone appeared to increase the risk of death (OR 3.36, 95% CI 1.36–8.30, P = .009).

Conclusion

In patients with an ICD, both AADs (amiodarone) and CA reduce the risk of recurrent VT compared to control medical therapy, with no significant difference between the 2 treatments. AADs are also associated with a reduction of inappropriate ICD therapies. The significant reduction of recurrent VT episodes does not appear to result in a mortality benefit, with a potential for increased mortality with amiodarone.

Introduction

Sustained ventricular tachycardias (VTs) represent the most frequent cause of sudden cardiac death. Over the last decade, after the results of pivotal clinical trials showing the efficacy of implantable cardioverter-defibrillators (ICDs) in reducing mortality attributable to sustained VT in high-risk patients, ICD use has dramatically expanded.1 Prevention of recurrent VT in patients with an ICD represents an important therapeutic target, given the demonstrated association between ICD shocks with impaired quality of life and increased mortality.2 Repetitive device intervention to terminate VT may damage the myocardium and worsen the underlying cardiac condition,3 and is associated with a significant burden of physical and psychological stress for patients. Recent evidences from primary prevention ICD populations have shown the benefit of device programming in reducing the risk of both appropriate and inappropriate device interventions and improving mortality.4 However, device programming does not prevent VT occurrence/recurrence, and many patients may continue to experience arrhythmia-related symptoms, including dizziness, palpitations, and syncope. Current approaches to prevent repeated ICD therapies include antiarrhythmic drugs (AADs) and catheter ablation (CA). Studies evaluating the efficacy of AAD or CA in preventing recurrent VT in ICD patients have provided mixed results with varying treatment effect.5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 In addition, whether prevention of VT translates into a mortality benefit is unclear. We performed a systematic review and meta-analysis of randomized controlled trials in order to better evaluate and compare the benefit of AAD or CA in preventing recurrent VT in patients with an ICD.

Section snippets

Methods

We followed a standard study protocol developed by the Cochrane Collaboration19 and adapted to the present meta-analysis as previously published.20

Search results and study selection

The search permitted the retrieval of 2131 citations. After removing duplicate citations, 1648 potentials studies were considered for further screening. All of the studies selected for further scrutiny were in English language. A total of 1612 studies were excluded after assessment of the full text. An additional 10 studies were excluded because of nonrandomized design. Of the randomized trials, 3 studies were excluded because they included only patients without an ICD, and 9 studies were

Discussion

This study was specifically designed to assess and compare the efficacy of AADs and CA in reducing the risk of recurrent VT in patients with ICD and is based on the statistical pooling of 14 randomized controlled trials that included >2000 patients. The major findings of our analysis are as follows. (1) both AADs and CA significantly reduce of the risk of recurrent VT leading to appropriate ICD interventions compared to control medical therapy, with no significant difference between the 2

Conclusion

This systematic review presents a meta-analysis of data from 14 randomized controlled studies that evaluated AADs or CA for the prevention of recurrent VT in patients with ICD and shows that both AADs (amiodarone) and CA reduce the risk of recurrent VT compared to control medical therapy, without significant differences between the 2 therapeutic strategies. AADs are also associated with a reduction of inappropriate ICD therapies. The significant reduction of recurrent VT episodes does not

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