title: Decision guidelines for prophylactic replacement of Björk-Shiley convexo-concave heart valves: impact on clinical practice.
abstract: BACKGROUND
  Because of risk of outlet strut fracture, prophylactic replacement should be considered for Björk-Shiley convexo-concave (BScc) valve recipients. We assessed the effects of epidemiological and decision-analytic guidelines on actual BScc valve replacement.
  
  
  RESULTS
  We performed a retrospective cohort study including all 2263 Dutch BScc patients with a mean follow-up of 11.3 years (range, 0 to 23 years). Outcomes were outlet strut fracture, mortality, and BScc valve replacement. For the surviving patients in 1992 (n=1330), we calculated the expected differences in life expectancy (LE) with and without BScc valve replacement according to decision guidelines developed in 1992. Differences in LE were compared with actual replacements. During 8 years of follow-up, there were 494 deaths (40%), and 11 patients had suffered outlet strut fracture. Of 1330 patients, 96 (10%) had undergone BScc valve replacement, particularly in years after introduction of initial and updated guidelines. One hundred seventeen patients (9%) had an estimated gain in LE after BScc valve replacement. These patients were more likely to undergo replacement than patients with an estimated loss of LE (hazard ratio, 6.6; 95% CI, 4.4 to 10; P<0.0001). A loss in LE after reoperation was predicted for 8 of 11 patients who experienced outlet strut fracture after guidelines were available.
  
  
  CONCLUSIONS
  Valve replacement for BScc heart valve patients was largely in concordance with guidelines in the Netherlands. Individualized guidelines that are based on high-quality epidemiological data and are updated and implemented rigorously can influence clinical practice in complex decision problems.
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: M J
authors.initials: MJ
authors.lastname: van Gorp
authors.forename: E W
authors.initials: EW
authors.lastname: Steyerberg
authors.forename: Y
authors.initials: Y
authors.lastname: Van der Graaf
mesh_terms: D000328:Adult; D000368:Aged; D002423:Cause of Death; D015331:Cohort Studies; D003661:Decision Support Techniques; D018572:Disease-Free Survival; D004630:Emergencies; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D019918:Heart Valve Prosthesis Implantation / Q000401:mortality / Q000706:statistics & numerical data*; D006801:Humans; D008017:Life Expectancy; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D017410:Practice Guidelines as Topic; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D015996:Survival Rate