Lack of efficacy of atenolol for the prevention of neurally mediated syncope in a highly symptomatic population: A prospective, double-blind, randomized and placebo-controlled study

OBJECTIVES This study was designed to evaluate the efficacy of atenolol for the long-term management of patients with vasovagal syncope. The primary h ypothesis was that atenolol is not superior to placebo for the treatment of vasovagal syncope. BACKGROUND There is no definitive well-controlled analysis of the efficacy of beta-adrenergic blocking agents in patients with recurrent vasovagal syn cope. METHODS This is a prospective, randomized, double-blind, placebo-controlled study. Fifty patients with recurrent vasovagal syncope were included (at l east two episodes in the last year). A baseline tilt test was performed. Tw enty patients (40%) had a positive tilt test. Intravenous atenolol prevente d a second positive tilt in five patients. The patients were randomized to receive either atenolol or a placebo (26 patients atenolol 50 mg/day, 24 pa tients placebo). The follow-up procedure lasted one year. The primary end p oint of the study was the time to first recurrence of syncope. RESULTS In the intention-to-treat analysis, the group treated with atenolol had a similar number of patients with recurrent syncopal episodes as the p lacebo group. The Kaplan-Meier actuarial estimates of time to first syncopa l recurrence showed that the probability of remaining between both curves ( patients treated with atenolol vs. the placebo) with a log-rank test p valu e of 0.4517. CONCLUSIONS The recurrence of neurocardiogenic syncope in highly symptomati c patients treated with atenolol is similar to that of patients treated wit h placebo. (C) 2001 by the American College of Cardiology.