title: Are treatments for vasovagal syncope effective? A meta-analysis.
abstract: BACKGROUND
  Therapies used to treat vaso-vagal syncope (VVS) recurrence have not been proven effective in single studies.
  
  
  METHODS
  Comprehensive 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.
  
  
  RESULTS
  α-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).
  
  
  CONCLUSIONS
  This 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.
authors.affiliation: Department of Internal Medicine, University of Iowa Hospitals and Clinics, United States. ankurvyas7@gmail.com
authors.forename: Ankur
authors.initials: A
authors.lastname: Vyas
authors.forename: Paari Dominic
authors.initials: PD
authors.lastname: Swaminathan
authors.forename: Miriam B
authors.initials: MB
authors.lastname: Zimmerman
authors.forename: Brian
authors.initials: B
authors.lastname: Olshansky
mesh_terms: D000322:Adrenergic Agonists / Q000627:therapeutic use; D002986:Clinical Trials as Topic / Q000379:methods; D006801:Humans; D017367:Selective Serotonin Reuptake Inhibitors / Q000627:therapeutic use; D019462:Syncope, Vasovagal / Q000175:diagnosis* / Q000628:therapy*; D018667:Tilt-Table Test / Q000379:methods; D016896:Treatment Outcome
chemical_list: D000322:Adrenergic Agonists; D017367:Selective Serotonin Reuptake Inhibitors