title: Clinical value of post-percutaneous coronary intervention fractional flow reserve value: A systematic review and meta-analysis.
abstract: BACKGROUND
  Fractional flow reserve (FFR) prior to percutaneous coronary intervention (PCI) is useful to guide treatment. Whether post-PCI FFR assessment might have clinical impact is controversial. The aim of this study is to evaluate the range of post-PCI FFR values and analyze the relationship between post-PCI FFR and clinical outcomes.
  
  
  METHODS
  We systematically searched the PubMed, EMBASE, and Cochrane Library databases with cross-referencing of articles reporting post-PCI FFR and correlating post-PCI FFR values and clinical outcomes. The outcomes of interest were the immediate post-PCI FFR values and the correlations between post-PCI FFR and the incidence of repeat intervention and major adverse cardiac events (MACE).
  
  
  RESULTS
  From 1995 to 2015, a total of 105 studies (n = 7470) were included, with 46 studies reporting post-PCI FFR and 59 studies evaluating relationship between post-PCI and clinical outcomes up to 30 months after PCI. Overall, post-PCI FFR values demonstrated a normal distribution with a mean value of 0.90 ± 0.04. There was a positive correlation between the percentage of stent use and post-PCI FFR (P < .0001). Meta-regression analysis indicated that higher post-PCI FFR values were associated with reduced rates of repeat intervention (P < .0001) and MACE (P = .0013). A post-PCI FFR ≥0.90 was associated with significantly lower risk of repeat PCI (odds ratio 0.43, 95% CI 0.34-0.56, P < .0001) and MACE (odds ratio 0.71, 95% CI 0.59-0.85, P = .0003).
  
  
  CONCLUSIONS
  FFR measurement after PCI was associated with prognostic significance. Further investigation is required to assess the role of post-PCI FFR and validate cutoff values in contemporary clinical practice.
authors.affiliation: Cardiology Department, Quebec Heart-Lung Institute, Quebec, Quebec, Canada.
authors.forename: Goran
authors.initials: G
authors.lastname: Rimac
authors.affiliation: Stanford University Medical Center, Stanford, CA.
authors.forename: William F
authors.initials: WF
authors.lastname: Fearon
authors.affiliation: Cardiovascular Center Aalst, OLV Clinic, Aalst, Belgium.
authors.forename: Bernard
authors.initials: B
authors.lastname: De Bruyne
authors.affiliation: Stanford University Medical Center, Stanford, CA.
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Ikeno
authors.affiliation: Department of Cardiovascular Medicine, Gifu Heart Center, Gifu, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Matsuo
authors.affiliation: Hungarian Institute of Cardiology, Budapest, Hungary.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Piroth
authors.affiliation: Cardiology Department, Quebec Heart-Lung Institute, Quebec, Quebec, Canada.
authors.forename: Olivier
authors.initials: O
authors.lastname: Costerousse
authors.affiliation: Cardiology Department, Quebec Heart-Lung Institute, Quebec, Quebec, Canada. Electronic address: Olivier.bertrand@crhl.ulaval.ca.
authors.forename: Olivier F
authors.initials: OF
authors.lastname: Bertrand
mesh_terms: D000328:Adult; D000368:Aged; D023921:Coronary Stenosis / Q000503:physiopathology* / Q000628:therapy; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention; D015607:Stents