Are treatments for vasovagal syncope effective? A meta-analysis

BackgroundTherapies used to treat vaso-vagal syncope (VVS) recurrence have not been proven effective in single studies.MethodsComprehensive search of PubMed, EMBASE and Cochrane Central databases of published trials was done. Randomized or non-randomized studies, comparing the intervention of interest to control group(s), with the endpoint of spontaneous recurrence or syncope on head-up tilt test, were included. Data were extracted on an intention-to-treat basis. Study heterogeneity was analyzed by Cochran's Q statistics. A random-effect analysis was used.Resultsα-adrenergic agonists were found effective (n = 400, OR 0.19, CI 0.06-0.62, p < 0.05) in preventing VVS recurrence. β-blockers were not found to be effective when only randomized studies comparing β-blockers to non-pharmacologic agents were assessed (9 studies, n = 583, OR 0.48, CI 0.22-1.04, p = 0.06). Tilt-training had no effect when only randomized studies were considered (4 studies, n = 298, OR 0.47, CI 0.21-1.05, p = 0.07). Selective serotonin reuptake inhibitors were found effective (n = 131, OR 0.28, CI 0.10-0.74, p < 0.05), though the analysis contained only 2 studies. Pacemakers were found effective in preventing syncope recurrence when all studies were analyzed (n = 463, OR 0.13, CI 0.05-0.36, p < 0.05). However, studies comparing active pacemaker to sensing mode only did not show benefit (3 studies, n = 162, OR 0.45, CI 0.09-2.14, p = 0.32).ConclusionsThis meta-analysis highlights the totality of evidence for commonly used medications used to treat VVS, and the requirement for larger, double-blind, placebo controlled trials with longer follow-up.