title: Usefulness of microsimulation to translate valve performance into patient outcome: patient prognosis after aortic valve replacement with the Carpentier-Edwards supra-annular valve.
abstract: OBJECTIVE
  Numerous reports have been published documenting the results of aortic valve replacement. It is often not easy to translate these outcomes involving the condition of the valve into the actual consequences for the patient. We previously developed an alternative method to study outcome after aortic valve replacement that allows direct estimation of patient outcome after aortic valve replacement: microsimulation modeling. The goal of this article is to provide insight into microsimulation methodology and to give an overview of the advantages and disadvantages of simulation methods (in particular microsimulation) in comparison with standard methods of outcome analysis.
  
  
  METHODS
  By using a primary dataset containing 1847 patients and 14,429 patient-years, advantages and disadvantages of standard methods of outcome analysis are discussed, and the potential role of microsimulation is illustrated by means of a step-by-step explanation of building, testing, and using such a model.
  
  
  RESULTS
  Total life expectancy, event-free life expectancy, and reoperation-free life expectancy for a 65-year-old male patient were 10.6 years, 9.2 years, and 9.8 years, respectively. Lifetime risk of reoperation due to structural valve deterioration was 13.3%.
  
  
  CONCLUSIONS
  Microsimulation is capable of providing accurate estimates of age-related life expectancy and lifetime risk of reoperation for patients who underwent aortic valve replacement with the Carpentier-Edwards supra-annular valve. It provides a useful tool to facilitate and optimize the choice for a specific heart valve prosthesis in a particular patient.
authors.affiliation: Department of Cardio-thoracic Surgery, Erasmus University Medical Center, Rotterdam, The Netherlands. m.vangeldorp@erasmusmc.nl
authors.forename: Martijn W A
authors.initials: MW
authors.lastname: van Geldorp
authors.forename: W R Eric
authors.initials: WR
authors.lastname: Jamieson
authors.forename: A Pieter
authors.initials: AP
authors.lastname: Kappetein
authors.forename: John P A
authors.initials: JP
authors.lastname: Puvimanasinghe
authors.forename: Marinus J C
authors.initials: MJ
authors.lastname: Eijkemans
authors.forename: Gary L
authors.initials: GL
authors.lastname: Grunkemeier
authors.forename: Johanna J M
authors.initials: JJ
authors.lastname: Takkenberg
authors.forename: Ad J J C
authors.initials: AJ
authors.lastname: Bogers
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis; D003198:Computer Simulation; D005260:Female; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D011379:Prognosis; D011474:Prosthesis Design