title: Radial access in patients with acute coronary syndrome without persistent ST-segment elevation: Systematic review, collaborative meta-analysis, and meta-regression.
abstract: BACKGROUND
  Consistent evidence of benefit exists for radial access (RA) in ST-elevation acute myocardial infarction (STEMI). Patients with non ST-elevation acute coronary syndrome (NSTE-ACS) have a more varied ischemic and bleeding profile. No randomized trial of vascular access ever focused on NSTE-ACS and landmark studies did not provide conclusive results in this heterogeneous subset of patients.
  
  
  METHODS
  We assessed in a meta-analysis whether RA is associated with improved outcomes in NSTE-ACS patients. Included studies had to meet the following criteria: 1) enrolling patients with NSTE-ACS undergoing invasive management; 2) reporting outcomes with respect to RA as compared with femoral access (FA); 3) reporting short-term (procedural, in-hospital and up to 30-day) or long-term clinical outcomes. Studies were pooled with fixed and random effects models and heterogeneity was investigated by weighted meta-regression.
  
  
  RESULTS
  Eleven studies were included encompassing 131.339 patients, 46.451 receiving RA and 84.888 receiving FA. Thirty-day mortality and MACE were lower with RA (p<0.001 with fixed effects, p=NS with random effects model), but these results depended on one large observational database. Major bleeding was consistently reduced by RA (p<0.001), albeit an inverse relationship with the proportion of patients in each study receiving FA and experiencing major bleeding was evident. The association of RA with reduced long-term mortality was of borderline significance (p=0.054 with random-effects, p=0.001 with fixed-effect model) and also depended on major bleeding in FA patients.
  
  
  CONCLUSIONS
  RA is associated with better outcomes as compared with FA in NSTE-ACS, although this observation is influenced by nonrandomized comparisons. Large heterogeneity exists among studies.
  
  
  BACKGROUND
  This study is registered in the PROSPERO database (CRD42015029459).
authors.affiliation: Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy. Electronic address: giuseppeando1975@gmail.com.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Andò
authors.affiliation: Institute of Cardiology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Italo
authors.initials: I
authors.lastname: Porto
authors.affiliation: ACTION Study Group, Institut de Cardiologie, Centre Hospitalier Universitaire Pitié-Salpêtriėre (AP-HP), Paris, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Montalescot
authors.affiliation: Cardiovascular and Neurological Department, Azienda Ospedaliera Arezzo, Arezzo, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Bolognese
authors.affiliation: Institute of Cardiology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Trani
authors.affiliation: Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Oreto
authors.affiliation: Department of Medicine, Stanford University, Stanford, CA, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Harrington
authors.affiliation: Brigham and Women's Hospital Heart & Vascular Center and Harvard Medical School, Boston, MA, USA.
authors.forename: Deepak L
authors.initials: DL
authors.lastname: Bhatt
mesh_terms: D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery*; D017023:Coronary Angiography / Q000379:methods; D006801:Humans; D064887:Observational Studies as Topic / Q000379:methods; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D017534:Radial Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D000072657:ST Elevation Myocardial Infarction / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery*
keywords: Acute coronary syndrome; Percutaneous coronary intervention; Radial access