Beta-blocker use and survival in patients with ventricular fibrillation orsymptomatic ventricular tachycardia: The Antiarrhythmics Versus Implantable Defibrillators (AVID) trial

OBJECTIVES To evaluate whether use of beta-adrenergic blocking agents, alon e or in combination with specific antiarrhythmic therapy, is associated wit h improved survival in persons with ventricular fibrillation (VF) or sympto matic 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 pati ents with VF or symptomatic VT followed in the Antiarrhythmics Versus Impla ntable Defibrillators (AVID) trial through December 31, 1996 was assessed u sing Cox proportional hazards analysis. RESULTS The 817 (28%) patients discharged from hospital receiving beta-bloc kers 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-b lockade was not significantly associated with survival in randomized or in eligible, nonrandomized patients treated with specific antiarrhythmic thera py. After adjustment, beta-blockade remained unrelated to survival in rando mized 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 = 0.8 8; 95% CI 0.55 to 1.40; p = 0.58). In contrast, beta-blockade was independe ntly associated with improved survival in eligible, nonrandomized patients who were not treated with specific antiarrhythmic therapy (n = 412; adjuste d RR = 0.47; 95% CI 0.25 to 0.88; p = 0.018). CONCLUSIONS Beta-blocker use was independently associated with improved sur vival in patients with VF or symptomatic VT who were not treated with speci fic antiarrhythmic therapy, but a protective effect was not prominent in pa tients already receiving amiodarone or a defibrillator. (C) 1999 by the Ame rican College of Cardiology.