title: Long-term clinical and echocardiographic follow-up of the Freestyle stentless aortic bioprosthesis.
abstract: BACKGROUND
  Stentless aortic bioprostheses were designed to provide enhanced hemodynamic performance and potentially greater longevity. The present report describes the outcomes of patients with the Freestyle stentless bioprosthesis followed for ≤18 years.
  
  
  RESULTS
  Between 1993 and 2011, 430 patients underwent primary aortic valve replacement with a Freestyle bioprosthesis in the subcoronary position. Mean age was 68.2 ± 8.2 years. All of the clinical and echocardiographic data were collected prospectively. Mean overall follow-up was 9.1 ± 4.4 years and was complete in all of the patients. In-hospital mortality was 3.5% (n=15). Overall, 10- and 15-year survival were 60.7% and 35.0%, respectively. Fifty-one patients required reoperation during follow-up, including 27 for structural valve deterioration (SVD). Overall, freedom from reoperation was 91.0% and 75.0% at 10 and 15 years, whereas freedom from reoperation for SVD was 95.9% and 82.3%, respectively. At 10 and 15 years, freedom from reoperation for SVD was 94.0% and 62.6% for patients <60 years of age and 96.3% and 88.4% for patients ≥60 years of age (P=0.002). The median time to explant for SVD was 10.7 years. SVD presented mostly as acute, severe aortic insufficiency attributed to leaflet tear (77.8%). The independent risk factors for reoperation for SVD were age <60 years (P=0.001) and dyslipidemia (P=0.02).
  
  
  CONCLUSIONS
  Aortic valve replacement with the Freestyle bioprosthesis in a subcoronary position provides good long-term clinical and echocardiographic outcomes for patients >60 years of age. Severe aortic insufficiency with leaflet tear is the major mode of SVD leading to reoperation in these patients.
authors.affiliation: Division of Cardiac Surgery, Quebec Heart and Lung University Institute, 2725 Chemin Ste-Foy, Quebec City, Quebec, Canada G1V 4G5. siamak.mohammadi@fmed.ulaval.ca
authors.forename: Siamak
authors.initials: S
authors.lastname: Mohammadi
authors.forename: Vincent
authors.initials: V
authors.lastname: Tchana-Sato
authors.forename: Dimitri
authors.initials: D
authors.lastname: Kalavrouziotis
authors.forename: Pierre
authors.initials: P
authors.lastname: Voisine
authors.forename: Daniel
authors.initials: D
authors.lastname: Doyle
authors.forename: Richard
authors.initials: R
authors.lastname: Baillot
authors.forename: Sandro
authors.initials: S
authors.lastname: Sponga
authors.forename: Jacques
authors.initials: J
authors.lastname: Metras
authors.forename: Jean
authors.initials: J
authors.lastname: Perron
authors.forename: François
authors.initials: F
authors.lastname: Dagenais
mesh_terms: D000367:Age Factors; D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D001022:Aortic Valve Insufficiency / Q000453:epidemiology / Q000601:surgery; D001705:Bioprosthesis / Q000706:statistics & numerical data; D018572:Disease-Free Survival; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis / Q000706:statistics & numerical data; D017052:Hospital Mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000401:mortality / Q000601:surgery; D011446:Prospective Studies; D011474:Prosthesis Design; D012086:Reoperation / Q000706:statistics & numerical data; D016896:Treatment Outcome; D014463:Ultrasonography