title: Mitral Valve Clip for Treatment of Mitral Regurgitation: An Evidence-Based Analysis.
abstract: BACKGROUND
  Many of the 500,000 North American patients with chronic mitral regurgitation may be poor candidates for mitral valve surgery.
  
  
  OBJECTIVE
  The objective of this study was to investigate the comparative effectiveness, harms, and cost-effectiveness of percutaneous mitral valve repair using mitral valve clips in candidates at prohibitive risk for surgery.
  
  
  METHODS
  We searched articles in MEDLINE, Embase, and the Cochrane Library published from 1994 to February 2014 for evidence of effectiveness and harms; for economic literature we also searched NHS EED and Tufts CEA registry. Grey literature was also searched.
  
  
  METHODS
  Primary studies were sought from existing systematic reviews that had employed reliable search and screening methods. Newer studies were sought by searching the period subsequent to the last search date of the review. Two reviewers screened records and assessed study validity. We used the Cochrane risk of bias tool for randomized, generic assessment for non-randomized studies, and the Phillips checklist for economic studies.
  
  
  RESULTS
  Ten studies including 1 randomized trial were included. The majority of the direct comparative evidence compared the mitral valve clip repair with surgery in patients not particularly at prohibitive surgical risk. Irrespective of degenerative or functional chronic mitral regurgitation etiology, evidence of effectiveness and harms is inconclusive and of very low quality. Very-low-quality evidence indicates that percutaneous mitral valve clip repair may provide a survival advantage, at least during the first 1 to 2 years, particularly in medically managed chronic functional mitral regurgitation. Because of limitations in the design of studies, the cost-effectiveness of mitral valve clips in patients at prohibitive risk for surgery also could not be established.
  
  
  CONCLUSIONS
  Because of serious concerns of risk of bias, indirectness, and imprecision, evidence is of very low quality.
  
  
  CONCLUSIONS
  No meaningful conclusions can be drawn about the comparative effectiveness, harms, and cost-effectiveness of mitral valve clips in the population with chronic mitral regurgitation who are at prohibitive risk for surgery.
authors.affiliation: Ottawa Hospital Research Institute, Ottawa, Ontario.
authors.forename: Mohammed T
authors.initials: MT
authors.lastname: Ansari
authors.affiliation: Ottawa Hospital Research Institute, Ottawa, Ontario.
authors.forename: Nadera
authors.initials: N
authors.lastname: Ahmadzai
authors.affiliation: Brunel University London, Uxbridge, Middlesex, England, United Kingdom.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Coyle
authors.affiliation: Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario MAY 2015.
authors.forename: Doug
authors.initials: D
authors.lastname: Coyle
authors.affiliation: Ottawa Hospital Research Institute, Ottawa, Ontario.
authors.forename: David
authors.initials: D
authors.lastname: Moher
mesh_terms: D003362:Cost-Benefit Analysis; D019317:Evidence-Based Medicine; D019918:Heart Valve Prosthesis Implantation / Q000191:economics / Q000295:instrumentation / Q000379:methods; D006801:Humans; D008943:Mitral Valve / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000191:economics / Q000601:surgery; D012196:Review Literature as Topic; D012307:Risk Factors; D013525:Surgical Instruments; D016896:Treatment Outcome