title: Twenty year comparison of a Bjork-Shiley mechanical heart valve with porcine bioprostheses.
abstract: OBJECTIVE
  To compare survival and outcome in patients receiving a mechanical or bioprosthetic heart valve prosthesis.
  
  
  METHODS
  Randomised prospective trial.
  
  
  METHODS
  Tertiary cardiac centre.
  
  
  METHODS
  Between 1975 and 1979, patients were randomised to receive either a Bjork-Shiley or a porcine prostheses. The mitral valve was replaced in 261 patients, the aortic in 211, and both valves in 61 patients. Follow up now averages 20 years.
  
  
  METHODS
  Death, reoperation, bleeding, embolism, and endocarditis.
  
  
  RESULTS
  After 20 years there was no difference in survival (Bjork-Shiley v porcine prosthesis (mean (SEM)): 25.0 (2.7)% v 22.6 (2.7)%, log rank test p = 0.39). Reoperation for valve failure was undertaken in 91 patients with porcine prostheses and in 22 with Bjork-Shiley prostheses. An analysis combining death and reoperation as end points confirmed that Bjork-Shiley patients had improved survival with the original prosthesis intact (23.5 (2.6)% v 6.7 (1.6)%, log rank test p < 0.0001); this difference became apparent after 8-10 years in patients undergoing mitral valve replacement, and after 12-14 years in those undergoing aortic valve replacement. Major bleeding was more common in Bjork-Shiley patients (40.7 (5.4)% v 27.9 (8.4)% after 20 years, p = 0.008), but there was no significant difference in major embolism or endocarditis.
  
  
  CONCLUSIONS
  Survival with an intact valve is better among patients with the Bjork-Shiley spherical tilting disc prosthesis than with a porcine prosthesis but there is an attendant increased risk of bleeding.
authors.affiliation: Department of Cardiology, Royal Infirmary of Edinburgh, Edinburgh, UK.
authors.forename: H
authors.initials: H
authors.lastname: Oxenham
authors.forename: P
authors.initials: P
authors.lastname: Bloomfield
authors.forename: D J
authors.initials: DJ
authors.lastname: Wheatley
authors.forename: R J
authors.initials: RJ
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Cunningham
authors.forename: R J
authors.initials: RJ
authors.lastname: Prescott
authors.forename: H C
authors.initials: HC
authors.lastname: Miller
mesh_terms: D000818:Animals; D001021:Aortic Valve; D001705:Bioprosthesis; D016063:Blood Loss, Surgical; D004617:Embolism / Q000209:etiology; D004697:Endocarditis, Bacterial / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D011446:Prospective Studies; D012086:Reoperation; D016019:Survival Analysis; D013552:Swine; D016896:Treatment Outcome