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
Ah. Madrid et al., 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, J AM COL C, 37(2), 2001, pp. 554-559
Citations number
34
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
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.