title: Meta-analysis on the impact of percutaneous coronary intervention of chronic total occlusions on left ventricular function and clinical outcome.
abstract: BACKGROUND
  Percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) may have a beneficial effect on survival through a better-preserved or improved LVEF. Current literature consists of small observational studies therefore we performed a weighted meta-analysis on the impact of revascularization of CTOs on left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV) and long-term mortality.
  
  
  METHODS
  We conducted a meta-analysis evaluating LVEF before and after CTO PCI and long-term mortality. No language or time restrictions were applied. References from the identified articles and reviews were examined to find additional relevant manuscripts.
  
  
  RESULTS
  Of the 812 citations, 34 studies performed between 1987-2014 in 2243 patients were eligible for LVEF and 27 studies performed between 1990-2013 in 11,085 patients with success and 4347 patients that failed CTO PCI were eligible for long-term mortality. After successful CTO PCI, LVEF increased with 4.44% (95% CI: 3.52-5.35, p<0.01) compared to baseline. In a small cohort of ~70 patients, no significant difference in LVEF was observed after non-successful CTO PCI or reocclusion. Additionally, 8 studies reported the change in left ventricular end-diastolic volume (LVEDV) in a total of 412 patients. LVEDV decreased with 6.14 ml/m(2) (95% CI: -9.31 to -2.97, p<0.01). Successful CTO PCI was also associated with reduced mortality in comparison with failed CTO PCI (OR: 0.52, 95% CI: 0.43-0.62, p-value<0.01).
  
  
  CONCLUSIONS
  The current meta-analysis revealed that successful recanalization of a CTO resulted in an overall improvement of 4.44% absolute LVEF points, reduced adverse remodeling and an improvement of survival (OR: 0.52).
authors.affiliation: Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Loes P
authors.initials: LP
authors.lastname: Hoebers
authors.affiliation: Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Bimmer E
authors.initials: BE
authors.lastname: Claessen
authors.affiliation: Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Joelle
authors.initials: J
authors.lastname: Elias
authors.affiliation: Mount Sinai Medical Center, New York, NY, United States.
authors.forename: George D
authors.initials: GD
authors.lastname: Dangas
authors.affiliation: Mount Sinai Medical Center, New York, NY, United States.
authors.forename: Roxana
authors.initials: R
authors.lastname: Mehran
authors.affiliation: Academic Medical Center, University of Amsterdam, The Netherlands. Electronic address: j.p.henriques@amc.uva.nl.
authors.forename: José P S
authors.initials: JP
authors.lastname: Henriques
mesh_terms: D002908:Chronic Disease; D054059:Coronary Occlusion / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D012307:Risk Factors; D013318:Stroke Volume; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: CTO; Chronic total occlusion; LVEDV; LVEF; Left ventricular function and mortality; Meta-analysis; Mortality; Percutaneous coronary intervention