title: Decision-making in aortic valve replacement: bileaflet mechanical valves versus stented bioprostheses.
abstract: BACKGROUND
  Valve prosthesis selection for patients who require aortic valve replacement is dependent on several interrelated factors. Often, more than one valve type seems suitable for the individual patient and selection of a valve type may be difficult.
  
  
  METHODS
  The application of an evidence-based microsimulation model as an objective tool to support the choice between a bileaflet mechanical prosthesis and a stented bioprosthesis in the individual patient is described. In addition, a pilot study investigating the effect of knowledge gained by this microsimulation model on prosthetic valve choice by cardiothoracic surgeons and cardiologists is presented for two hypothetical patients.
  
  
  RESULTS
  After implantation of a mechanical valve, bleeding and thromboembolism are common, especially in the elderly. After implantation of a bioprosthesis, reoperation for structural failure is the most important valve-related complication, especially in younger patients. Life expectancy after aortic valve replacement is markedly reduced compared with the general Dutch age-matched population, regardless of the type of valve implanted. In the pilot study knowledge gained by the microsimulation model caused a shift in the preference towards a mechanical prosthesis in clinical experts.
  
  
  CONCLUSIONS
  Microsimulation incorporating current epidemiological data provides an objective tool to estimate prognosis for individual patients after aortic valve replacement with different valve prostheses. It may develop towards a useful clinical decision support system for valve prosthesis selection.
authors.forename: J J M
authors.initials: JJ
authors.lastname: Takkenberg
authors.forename: J P A
authors.initials: JP
authors.lastname: Puvimanasinghe
authors.forename: L A
authors.initials: LA
authors.lastname: van Herwerden
authors.forename: M J C
authors.initials: MJ
authors.lastname: Eijkemans
authors.forename: E W
authors.initials: EW
authors.lastname: Steyerberg
authors.forename: J D F
authors.initials: JD
authors.lastname: Habbema
authors.forename: A J J C
authors.initials: AJ
authors.lastname: Bogers
keywords: aortic valve replacement; clinical decision support system; mechanical versus bioprostheses; microsimulation; prosthetic valve choice