title: Survival advantage of stentless aortic bioprostheses.
abstract: BACKGROUND
  Bioprostheses (BPs) are used to avoid anticoagulation after aortic valve replacement (AVR) in patients over 65 years of age. Stentless BPs offer established hemodynamic benefits. We sought to determine whether these advantages translate into improved survival.
  
  
  METHODS
  Between 1993 and 1997, follow-up data (for Food and Drug Administration submission) were collected prospectively for 160 consecutive, unselected hospital survivors who received the Freestyle valve (FS). Equivalent data were collected for 247 Carpentier-Edwards (CE) porcine xenograft patients. Detailed comparative statistical analysis was used to compare events and survival between the groups. Follow-up was 100% complete for the FS (5.2 years maximum; mean 3.2+/-1.0 years) group and 98% (7.2 years maximum; mean 3.8+/-2.0 years) for CE.
  
  
  RESULTS
  The groups were well matched in age (FS, 73+/-6 years; CE, 74+/-6 years), gender (FS, 58% male; CE, 62% male), ventricular function, and number of patients requiring coronary grafts (FS, 41%; CE, 37%). Actuarial survival at 5 years was 84% for FS versus 69% for CE (p = 0.023 Kaplan Meier, p = 0.009 Cox). Annual mortality rates were 3.6% for FS versus 7.1% for CE (p = 0.001). Thromboembolic rate was 0.8% per year for FS and 2.4% for CE (p = 0.024) without a difference in cardiac rhythm. Incidence of nonstructural dysfunction (paravalvular leak) was 0.2% for FS versus 1.3% for CE (p = 0.020).
  
  
  CONCLUSIONS
  By 5 years, the stentless valve patients had improved survival and reduced adverse events. Though differences in durability are yet to be proved, our findings support the use of stentless bioprostheses in this age group.
authors.affiliation: Department of Cardiac Surgery, Oxford Heart Centre, John Radcliffe Hospital, Headington, United Kingdom. swestaby@ahf.org.uk
authors.forename: S
authors.initials: S
authors.lastname: Westaby
authors.forename: M
authors.initials: M
authors.lastname: Horton
authors.forename: X Y
authors.initials: XY
authors.lastname: Jin
authors.forename: T
authors.initials: T
authors.lastname: Katsumata
authors.forename: O
authors.initials: O
authors.lastname: Ahmed
authors.forename: S
authors.initials: S
authors.lastname: Saito
authors.forename: H H
authors.initials: HH
authors.lastname: Li
authors.forename: G L
authors.initials: GL
authors.lastname: Grunkemeier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis; D005260:Female; D005500:Follow-Up Studies; D019918:Heart Valve Prosthesis Implantation / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D015996:Survival Rate