title: Procedural volume and outcomes with radial or femoral access for coronary angiography and intervention.
abstract: OBJECTIVE
  The study sought to evaluate the relationship between procedural volume and outcomes with radial and femoral approach.
  
  
  BACKGROUND
  RIVAL (RadIal Vs. femorAL) was a randomized trial of radial versus femoral access for coronary angiography/intervention (N = 7,021), which overall did not show a difference in primary outcome of death, myocardial infarction, stroke, or non-coronary artery bypass graft major bleeding.
  
  
  METHODS
  In pre-specified subgroup analyses, the hazard ratios for the primary outcome were compared among centers divided by tertiles and among individual operators. A multivariable Cox proportional hazards model was used to determine the independent effect of center and operator volumes after adjusting for other variables.
  
  
  RESULTS
  In high-volume radial centers, the primary outcome was reduced with radial versus femoral access (hazard ratio [HR]: 0.49; 95% confidence interval [CI]: 0.28 to 0.87) but not in intermediate- (HR: 1.23; 95% CI: 0.88 to 1.72) or low-volume centers (HR: 0.83; 95% CI: 0.52 to 1.31; interaction p = 0.021). High-volume centers enrolled a higher proportion of ST-segment elevation myocardial infarction (STEMI). After adjustment for STEMI, the benefit of radial access persisted at high-volume radial centers. There was no difference in the primary outcome between radial and femoral access by operator volume: high-volume operators (HR: 0.79; 95% CI: 0.48 to 1.28), intermediate (HR: 0.87; 95% CI: 0.60 to 1.27), and low (HR: 1.10; 95% CI: 0.74 to 1.65; interaction p = 0.536). However, in a multivariable model, overall center volume and radial center volume were independently associated with the primary outcome but not femoral center volume (overall percutaneous coronary intervention volume HR: 0.92, 95% CI: 0.88 to 0.96; radial volume HR: 0.88, 95% CI: 0.80 to 0.97; and femoral volume HR: 1.00, 95% CI: 0.94 to 1.07; p = 0.98).
  
  
  CONCLUSIONS
  Procedural volume and expertise are important, particularly for radial percutaneous coronary intervention. (A Trial of Trans-radial Versus Trans-femoral Percutaneous Coronary Intervention [PCI] Access Site Approach in Patients With Unstable Angina or Myocardial Infarction Managed With an Invasive Strategy [RIVAL]; NCT01014273).
authors.affiliation: McMaster University and Population Health Research Institute, Hamilton Health Sciences, Hamilton, Ontario, Canada. Electronic address: sanjit.jolly@phri.ca.
authors.forename: Sanjit S
authors.initials: SS
authors.lastname: Jolly
authors.affiliation: University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Cairns
authors.affiliation: McMaster University and Population Health Research Institute, Hamilton Health Sciences, Hamilton, Ontario, Canada.
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
authors.affiliation: Tampere University Hospital and Heart Center, Tampere, Finland.
authors.forename: Kari
authors.initials: K
authors.lastname: Niemela
authors.affiliation: Université Paris-Diderot, Paris, France.
authors.forename: Philippe Gabriel
authors.initials: PG
authors.lastname: Steg
authors.affiliation: University of Adelaide, Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Matthew
authors.initials: M
authors.lastname: Worthley
authors.affiliation: Hopital Pasteur, Nice, France.
authors.forename: Emile
authors.initials: E
authors.lastname: Ferrari
authors.affiliation: Southlake Regional Health Centre, University of Toronto, Ontario, Canada.
authors.forename: Warren J
authors.initials: WJ
authors.lastname: Cantor
authors.affiliation: University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Anthony
authors.initials: A
authors.lastname: Fung
authors.affiliation: McMaster University and Population Health Research Institute, Hamilton Health Sciences, Hamilton, Ontario, Canada.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Valettas
authors.affiliation: McMaster University and Population Health Research Institute, Hamilton Health Sciences, Hamilton, Ontario, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Rokoss
authors.affiliation: Skane University Hospital, Lund, Sweden.
authors.forename: Goran K
authors.initials: GK
authors.lastname: Olivecrona
authors.affiliation: Charles University, Hospital Kralovske Vinohrady, Prague, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Widimsky
authors.affiliation: St. Michael's Hospital, University of Toronto, Ontario, Canada.
authors.forename: Asim N
authors.initials: AN
authors.lastname: Cheema
authors.affiliation: McMaster University and Population Health Research Institute, Hamilton Health Sciences, Hamilton, Ontario, Canada.
authors.forename: Peggy
authors.initials: P
authors.lastname: Gao
authors.affiliation: McMaster University and Population Health Research Institute, Hamilton Health Sciences, Hamilton, Ontario, Canada.
authors.forename: Shamir R
authors.initials: SR
authors.lastname: Mehta
mesh_terms: D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging* / Q000601:surgery*; D000368:Aged; D002406:Catheterization, Peripheral / Q000379:methods / Q000706:statistics & numerical data*; D017023:Coronary Angiography / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D005263:Femoral Artery; D006801:Humans; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D011379:Prognosis; D017534:Radial Artery
keywords: acute coronary syndrome(s); femoral access; percutaneous coronary intervention; procedural volume; radial access