title: Early valve replacement for aortic stenosis irrespective of symptoms results in better clinical survival: a meta-analysis of the current evidence.
abstract: OBJECTIVE
  Patients with severe, but asymptomatic aortic stenosis (AS) present a difficult clinical challenge. The conventional strategy is 'wait for symptoms' approach. However, some observational studies have suggested early aortic valve replacement (AVR) results in better outcome compared to late surgery. There are no randomised controlled trials comparing clinical outcome of early and late AVR. This meta-analysis is to examine the effect of the two approaches on clinical outcome in such patients.
  
  
  METHODS
  We searched the PubMed for published studies on asymptomatic AS and treatment. Four observational studies (N=976 patients) were suitable for inclusion in the analysis.
  
  
  RESULTS
  All four studies provided sufficient details. Using the subgroup of asymptomatic patients who underwent early surgery together or separately from the subgroup who had surgery after developing symptoms resulted in ORs of 0.17 and 0.16 respectively (p<0.00001) in favour of early AVR compared with conservational or late surgery.
  
  
  CONCLUSIONS
  Meta-analysis of the available observational studies has demonstrated highly significant clinical outcome in favour of early AVR compared with late surgery, suggesting that early surgical approach offers substantial survival benefit for severe asymptomatic AS patients.
authors.affiliation: Ultrasound Department, Beijing Anzhen Hospital, Capital Medical University, Beijing, China; Cardiology Heart Centre and Department of Public Health and Clinical Medicine, Umea University, Umea, Sweden.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Andrew
authors.initials: A
authors.lastname: Owen
authors.forename: Michael
authors.initials: M
authors.lastname: Henein
mesh_terms: D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000401:mortality* / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation / Q000401:mortality* / Q000639:trends; D006801:Humans; D064887:Observational Studies as Topic / Q000379:methods / Q000401:mortality; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome
keywords: Aortic stenosis; Asymptomatic; Valve replacement