M Brignole1, R Sutton. 1. Department of Cardiology, Ospedali del Tigullio, Via don Bobbio, 16033 Lavagna, Italy. mbrignole@ASL4.liguria.it
Abstract
BACKGROUND: After two recent controlled trials failed to prove superiority of cardiac pacing over placebo in patients affected by neurally mediated syncope, a widely accepted opinion is that cardiac pacing therapy is not very effective and that a strong placebo effect exists. AIM: To measure the effect of placebo pacing therapy. METHOD AND RESULTS: We compared the recurrence rate of syncope during placebo vs. no treatment in controlled trials of drug or pacing therapy. Syncope recurred in 38% of 252 patients randomized to placebo pooled from five trials vs. 34% of 881 patients randomized to no treatment pooled from eight trials. The corresponding recurrence rate with active cardiac pacing was 15% in 203 patients from six trials. CONCLUSIONS:Placebo is not an effective therapy for neurally mediated syncope. Different selection criteria in patients who are candidates for cardiac pacing-for example, presence, absence, or severity of the cardioinhibitory reflex may separate positive from negative trials.
RCT Entities:
BACKGROUND: After two recent controlled trials failed to prove superiority of cardiac pacing over placebo in patients affected by neurally mediated syncope, a widely accepted opinion is that cardiac pacing therapy is not very effective and that a strong placebo effect exists. AIM: To measure the effect of placebo pacing therapy. METHOD AND RESULTS: We compared the recurrence rate of syncope during placebo vs. no treatment in controlled trials of drug or pacing therapy. Syncope recurred in 38% of 252 patients randomized to placebo pooled from five trials vs. 34% of 881 patients randomized to no treatment pooled from eight trials. The corresponding recurrence rate with active cardiac pacing was 15% in 203 patients from six trials. CONCLUSIONS: Placebo is not an effective therapy for neurally mediated syncope. Different selection criteria in patients who are candidates for cardiac pacing-for example, presence, absence, or severity of the cardioinhibitory reflex may separate positive from negative trials.
Authors: Rajesh Subbiah; Pow-Li Chia; Lorne J Gula; George J Klein; Allan C Skanes; Raymond Yee; Andrew D Krahn Journal: Curr Cardiol Rev Date: 2013-11