title: Predicted patient outcome after aortic valve replacement with Medtronic Stentless Freestyle bioprostheses.
abstract: OBJECTIVE
  Knowledge on long-term patient outcome after implantation with the Medtronic Stentless Freestyle bioprosthesis is incomplete due to a limited follow up. In the present study, microsimulation was used to extrapolate the available primary data and to calculate the life expectancy and lifetime risks of valve-related events after aortic valve replacement (AVR) with the Freestyle bioprosthesis.
  
  
  METHODS
  Eleven-year follow up data from 725 patients (mean age 72 +/- 8 years; range: 36-92 years) who underwent AVR with a Medtronic Freestyle bio-prosthesis were used to calculate the hazards of structural valvular deterioration (SVD) and of other valve-related events. Age-dependent Weibull distributions were used to model SVD. These results were incorporated into a mathematical microsimulation model, which then calculated the long-term outcomes for patients of any given age and gender.
  
  
  RESULTS
  The annual hazards for thromboembolism and endocarditis were 2.9% and 0.45% per patient-year, respectively. For example, for a 72-year-old male patient the median time to SVD was 20.0 (17.8-22.4) years. The life expectancy, reoperation-free life expectancy and event-free life expectancy of this patient was 10.4, 9.7, and 7.2 years, respectively. The patient had a higher life expectancy compared to age and gender-matched persons in the general population. His lifetime risk of reoperation due to SVD was 15%.
  
  
  CONCLUSIONS
  The Medtronic Stentless Freestyle bioprosthesis performs well and offers a low lifetime risk of reoperation for elderly patients requiring AVR. The performance of the valve and the selective patient population might explain the higher life expectancy compared to age and gender-matched persons in the general population.
authors: Department of Cardio-Thoracic Surgery, Erasmus Medical Center, Rotterdam, The Netherlands. a.kappetein@erasmusmc.nl
authors: A Pieter
authors: AP
authors: Kappetein
authors: John P A
authors: JP
authors: Puvimanasinghe
authors: Johanna J M
authors: JJ
authors: Takkenberg
authors: Ewout W
authors: EW
authors: Steyerberg
authors: Ad J J C
authors: AJ
authors: Bogers
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve; D001705:Bioprosthesis / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000601:surgery*; D006350:Heart Valve Prosthesis / Q000009:adverse effects; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008017:Life Expectancy; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D018570:Risk Assessment; D016896:Treatment Outcome