title: Time-varying survival benefit of radial artery versus vein grafting: a multiinstitutional analysis.
abstract: BACKGROUND
  A survival benefit of radial artery use versus saphenous vein grafting in coronary artery bypass grafting (CABG) has been reported. We aimed to elucidate the relative radial artery survival benefit as a function of time after surgery from two independent CABG series.
  
  
  METHODS
  We compared 0- to 15-year survival with radial artery versus saphenous vein grafting in isolated, nonsalvage primary CABG with left internal thoracic artery to left anterior descending from two institutions: Ohio (radial artery [n=2,361; 61 years]; saphenous vein [n=2,547; 67 years]), and New York (radial artery [n=1,970; 58 years]; saphenous vein [n=2,974; 69 years]). Separate multivariate radial artery-use propensity models based on demographic, preoperative factors, intraoperative variables, and completeness of revascularization data were computed and used to derive propensity- and sex-matched CABG cohorts (1,799 [Ohio] and 995 [New York] pairs). A three-phase (early and late) mortality model was fit to Kaplan-Meier mortality estimates and used to derive relative radial artery versus saphenous vein hazard functions.
  
  
  RESULTS
  Radial artery use patterns and patient risk profiles differed substantially for New York and Ohio, with the New York radial artery cohort significantly younger and more male. Within-institution matched graft-type cohorts were well matched. Cumulative mortality was significantly better for radial artery at both institutions (p < 0.001 both). All mortality-time data were well described by the three-phase model, and the derived relative hazard functions were qualitatively and quantitatively similar for New York and Ohio, exhibiting maximal benefit between 0.5 and 5 years.
  
  
  CONCLUSIONS
  Despite substantial differences in radial artery use patterns during a 15-year period, our analysis in large propensity-matched radial artery and saphenous vein cohorts yielded remarkably similar, time-varying radial artery to saphenous vein survival benefit at both institutions. These converging findings based on two independent patient series extend currently available objective evidence in support of a radial artery survival advantage in CABG.
authors.affiliation: Department of Surgery, University of Toledo Medical Center, Toledo, Ohio; Mercy Saint Vincent Medical Center, Toledo, Ohio.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Schwann
authors.affiliation: Beth Israel Medical Center, New York, New York.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Tranbaugh
authors.affiliation: Beth Israel Medical Center, New York, New York.
authors.forename: Kamellia R
authors.initials: KR
authors.lastname: Dimitrova
authors.affiliation: Mercy Saint Vincent Medical Center, Toledo, Ohio; Anesthesiology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Milo C
authors.initials: MC
authors.lastname: Engoren
authors.affiliation: Mercy Saint Vincent Medical Center, Toledo, Ohio.
authors.forename: Ameer
authors.initials: A
authors.lastname: Kabour
authors.affiliation: Beth Israel Medical Center, New York, New York.
authors.forename: Darryl M
authors.initials: DM
authors.lastname: Hoffman
authors.affiliation: Beth Israel Medical Center, New York, New York.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Geller
authors.affiliation: Beth Israel Medical Center, New York, New York.
authors.forename: Wilson
authors.initials: W
authors.lastname: Ko
authors.affiliation: Department of Internal Medicine and Outcomes Research Unit, American University of Beirut, Beirut, Lebanon. Electronic address: rh106@aub.edu.lb.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Habib
mesh_terms: D001026:Coronary Artery Bypass / Q000379:methods*; D003324:Coronary Artery Disease / Q000401:mortality* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017534:Radial Artery / Q000637:transplantation*; D012501:Saphenous Vein / Q000637:transplantation*; D015996:Survival Rate; D013997:Time Factors