title: Twenty-five-year experience with the Björk-Shiley convexoconcave heart valve: a continuing clinical concern.
abstract: BACKGROUND
  The first Björk-Shiley convexoconcave (BSCC) prosthetic heart valves were implanted in 1978. The 25th anniversary provided a stimulus to summarize the research data relevant to BSCC valve fracture, patient management, and current clinical options.
  
  
  RESULTS
  Published and unpublished data on the risks of BSCC valve fracture and replacement were compiled, and strategies for identifying candidates for prophylactic valve reoperation were summarized. By December 2003, outlet strut fractures (OSFs), often with fatal outcomes, had been reported in 633 BSCC valves (0.7% of 86,000 valves implanted). Fractures still continue to occur, but average rates of OSFs in 60 degrees valves are now <0.1% per year. OSF risk varies markedly by valve characteristics, especially valve angle and size, with weaker effects associated with other manufacturing variables. OSF risks are mildly lower among women than men but decline sharply with advancing age. The risks of valve replacement typically greatly exceed those of OSF. By comparing individualized estimated risks of OSF versus valve replacement, guidelines have been developed to identify the small percentage of BSCC patients (mostly younger men) who would be expected to have a gain in life expectancy should reoperative surgery be performed.
  
  
  CONCLUSIONS
  Twenty-five years after the initial BSCC valve implants, fractures continue to occur. Continued monitoring of BSCC patients is needed to track and quantify risks and enable periodic updating of guidelines for patients and their physicians.
authors.affiliation: International Epidemiology Institute, Rockville, MD, USA. blotw@iei.ws
authors.forename: William J
authors.initials: WJ
authors.lastname: Blot
authors.forename: Michel A
authors.initials: MA
authors.lastname: Ibrahim
authors.forename: Tom D
authors.initials: TD
authors.lastname: Ivey
authors.forename: Donald E
authors.initials: DE
authors.lastname: Acheson
authors.forename: Ron
authors.initials: R
authors.lastname: Brookmeyer
authors.forename: Arthur
authors.initials: A
authors.lastname: Weyman
authors.forename: Joseph
authors.initials: J
authors.lastname: Defauw
authors.forename: J Kermit
authors.initials: JK
authors.lastname: Smith
authors.forename: Donald
authors.initials: D
authors.lastname: Harrison
mesh_terms: D005260:Female; D006350:Heart Valve Prosthesis / Q000009:adverse effects* / Q000266:history; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D008297:Male; D018579:Patient Selection; D011159:Population Surveillance; D017410:Practice Guidelines as Topic; D011475:Prosthesis Failure; D012086:Reoperation; D012306:Risk