Amiodarone Versus Implantable Defibrillator in Patients with Nonischemic Cardiomyopathy and Asymptomatic Nonsustained Ventricular Tachycardia study - AMIOVIRT

Description:

AMIOVIRT was designed to compare the effect of amiodarone and implantable converter defibrillator (ICD) on mortality in patients with nonischemic dilated cardiomyopathy (NIDCM) and asymptomatic, nonsustained ventricular tachycardia (NSVT).

Hypothesis:

Treatment with an implanted defibrillator would demonstrate a survival advantage compared with treatment with amiodarone in patients with nonischemic dilated cardiomyopathy and asymptomatic, nonsustained ventricular tachycardia.

Study Design

Study Design:

Patients Screened: 178
Patients Enrolled: 103
NYHA Class: Class II - 63% amiodarone and 64% ICD; Class III 24% and 16%
Mean Follow Up: mean 2.0 years
Mean Patient Age: mean age 59 years
Female: 30
Mean Ejection Fraction: Mean baseline LVEF 23% in amiodarone and 22% in ICD arm.

Patient Populations:

A NIDCM (defined as left ventricular dysfunction in the absence of CAD or disproportionate to the severity of CAD), ejection fraction <=35%, asymptomatic="" nsvt,="" new="" york="" heart="" association="" functional="" class="" i="" to="" iii,="" and="" age="">=18 years./html>

Exclusions:

Syncope, pregnancy, a contraindication to amiodarone or defibrillator therapy, or concomitant therapy with a Class I antiarrhythmic drug.

Primary Endpoints:

Total mortality.

Secondary Endpoints:

Sudden cardiac death (SCD), non-SCD, noncardiac death, syncope, arrhythmia-free survival, quality of life, and costs.

Drug/Procedures Used:

Patients were randomly assigned to have a defibrillator implanted (n=51) or to receive amiodarone (400 mg twice a day for 1 week, followed by 400 mg once a day for 51 weeks, and 300 mg once a day thereafter; n=52).

Concomitant Medications:

Optimal medical therapy with angiotensin-converting enzyme inhibitors, beta-blockers, and potassium-sparing diuretics was strongly encouraged.

Principal Findings:

There was no difference in survival at 1 year (90% vs 96%) or 3 years (88% vs 87%; p=0.8) in the amiodarone and ICD groups, respectively. Arrhythmia-free survival rates at 3 years trended higher with amiodarone vs ICD (73% and 63%, p=0.1). Syncope occurred in 5.8% of the patients treated with amiodarone and 3.9% of the patients treated with an ICD (p=0.7) during the duration of the study. Quality of life was also similar between the treatment arms at 1 year follow-up (p=NS). Costs trended lower during the first year of therapy with amiodarone vs ICD ($8,879 vs. $22,039, p=0.1).

Interpretation:

Among patients with nonischemic dilated cardiomyopathy and asymptomatic, nonsustained ventricular tachycardia, treatment with an ICD was not associated with a reduction in total mortality compared with treatment with amiodarone during a mean 2-year follow-up. On the contrary, amiodarone therapy was associated with a trend towards improved arrhythmia-free survival. ICD has been shown to be more effective for survival than pharmacologic therapy in the MUSTT and MADIT trials. However, these trials enrolled patients with prior CAD, unlike the present trial which enrolled patients with NIDCM and NSVT. Given the lack of difference in mortality and the trend toward lower costs with amiodarone, it is unclear what the first clear-cut choice of therapy should be in patients with NIDCM and NSVT. The small sample size in the present trial limits the conclusions that can be drawn.

References:

Strickberger SA et al. Amiodarone Versus Implantable Cardioverter-Defibrillator: Randomized Trial in Patients With Nonischemic Dilated Cardiomyopathy and Asymptomatic Nonsustained Ventricular Tachycardia‚ÄĒAMIOVIRT. J Am Coll Cardiol 2003;41:1707-12.

Presented at AHA 2000.

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Implantable Devices, SCD/Ventricular Arrhythmias

Keywords: Tachycardia, Ventricular, Quality of Life, Survival Rate, Syncope, Ventricular Dysfunction, Left, Defibrillators, Implantable, Cardiomyopathy, Dilated


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