title: Eight-year results after aortic valve replacement with the Freestyle stentless bioprosthesis.
abstract: OBJECTIVE
  We sought to describe the hemodynamic and clinical outcomes for the Freestyle aortic root bioprosthesis (Medtronic, Inc, Minneapolis, Minn) in a large multicenter cohort prospectively followed for 8 years.
  
  
  METHODS
  A total of 700 patients (651 [93%] >60 years of age) at 8 centers in North America were followed prospectively after aortic valve replacement with the Freestyle stentless bioprosthesis; the implant technique was subcoronary in 500, total root in 162, and root inclusion in 38. Follow-up was 3395 patient-years (4.9 +/- 2.3 years per patient). Clinical and echocardiographic follow-up was prospectively obtained at yearly intervals.
  
  
  RESULTS
  For the subcoronary, total root, and root inclusion groups, actuarial freedom from valve-related death was 96.8% (SE 3.0%), 92.3% (SE 7.7%), and 90.9% (SE 11.2%), respectively, and freedom from structural deterioration was 98.6% (SE 2.0%), 100.0% (SE 0.0%), and 100.0% (SE 0.0%), respectively. Hemodynamics remained excellent at 6 years. Freedom from moderate or more aortic regurgitation was 86.0% (SE 5.1%), 98.7% (SE 3.9%), and 97.3% (SE 6.6%), respectively. Gradients were slightly lower (P =.0009), and the effective orifice area (P =.02) and freedom from aortic regurgitation were slightly higher (P =.03) with total root than subcoronary implantation.
  
  
  CONCLUSIONS
  The Freestyle stentless aortic root bioprosthesis is a versatile option for aortic valve replacement. Measures of clinical outcomes and prosthesis durability remain excellent in multicenter follow-up through 8 years in a population predominantly older than 60 years at the time of the operation.
authors.affiliation: Department of Medicine, Division of Cardiology, University of Michigan, Ann Arbor, 48109, USA. dbach@umich.edu
authors.forename: David S
authors.initials: DS
authors.lastname: Bach
authors.forename: Neal D
authors.initials: ND
authors.lastname: Kon
authors.forename: Jean G
authors.initials: JG
authors.lastname: Dumesnil
authors.forename: Colleen F
authors.initials: CF
authors.lastname: Sintek
authors.forename: Donald B
authors.initials: DB
authors.lastname: Doty
mesh_terms: D000328:Adult; D000368:Aged; D001022:Aortic Valve Insufficiency / Q000000981:diagnostic imaging / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000601:surgery; D001705:Bioprosthesis; D015331:Cohort Studies; D015150:Echocardiography, Doppler; D005260:Female; D005500:Follow-Up Studies; D006334:Heart Function Tests; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology*; D049670:History, 17th Century; D006801:Humans; D008297:Male; D011183:Postoperative Complications; D011336:Probability; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D018570:Risk Assessment; D012720:Severity of Illness Index; D015607:Stents; D016896:Treatment Outcome