Clinical Studies
Beta-blocker use and survival in patients with ventricular fibrillation or symptomatic ventricular tachycardia: the antiarrhythmics versus implantable defibrillators (AVID) trial

https://doi.org/10.1016/S0735-1097(99)00234-XGet rights and content
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Abstract

OBJECTIVES

To evaluate whether use of beta-adrenergic blocking agents, alone or in combination with specific antiarrhythmic therapy, is associated with improved survival in persons with ventricular fibrillation (VF) or symptomatic ventricular tachycardia (VT).

BACKGROUND

The ability of beta-blockers to alter the mortality of patients with VF or VT receiving contemporary medical management is not well defined.

METHODS

Survival of 1,016 randomized and 2,101 eligible, nonrandomized patients with VF or symptomatic VT followed in the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial through December 31, 1996 was assessed using Cox proportional hazards analysis.

RESULTS

The 817 (28%) patients discharged from hospital receiving beta-blockers had less ventricular dysfunction, fewer symptoms of heart failure and a different pattern of medication use compared with patients not receiving beta-blockers. Before adjustment for important prognostic variables, beta-blockade was not significantly associated with survival in randomized or in eligible, nonrandomized patients treated with specific antiarrhythmic therapy. After adjustment, beta-blockade remained unrelated to survival in randomized or in eligible, nonrandomized patients treated with amiodarone alone (n = 1142; adjusted relative risk [RR] = 0.96; 95% confidence interval [CI] 0.64–1.45; p = 0.85) or a defibrillator alone (n = 1347; adjusted RR = 0.88; 95% CI 0.55 to 1.40; p = 0.58). In contrast, beta-blockade was independently associated with improved survival in eligible, nonrandomized patients who were not treated with specific antiarrhythmic therapy (n = 412; adjusted RR = 0.47; 95% CI 0.25 to 0.88; p = 0.018).

CONCLUSIONS

Beta-blocker use was independently associated with improved survival in patients with VF or symptomatic VT who were not treated with specific antiarrhythmic therapy, but a protective effect was not prominent in patients already receiving amiodarone or a defibrillator.

Abbreviations

ACE
angiotensin-converting enzyme
AVID
Antiarrhythmics Versus Implantable Defibrillators
CAMIAT
Canadian Amiodarone Myocardial Infarction Arrhythmia Trial
EMIAT
European Myocardial Infarct Amiodarone Trial
CI
confidence interval
ICD
implantable cardioverter defibrillator
LV
left ventricular
MI
myocardial infarction
NYHA
New York Heart Association
RR
relative risk
VF
ventricular fibrillation
VT
ventricular tachycardia

Cited by (0)

This study was supported by a contract (N01 HC-25117) with the National Heart, Lung, and Blood Institute. Dr. Exner is a Clinician-Scientist (phase I) of the Medical Research Council of Canada and Research Fellow of the Alberta Heritage Foundation for Medical Research.

1

See reference15for a listing of AVID investigators and sites.