title: Hemodynamic comparison between Trifecta and freestyle aortic valve during exercise in patients with small aortic root.
abstract: BACKGROUND
  Patients with a small aortic annulus, that is ≤ 23 mm, constitute a challenge for the surgeon, because they are at high risk of patient-prosthesis mismatch. Stentless valves provide better hemodynamic performance at rest and during exercise than stented valves, and are advocated in this group of patients. A new-generation stented valve, the Trifecta (St. Jude), has recently become available with improved hemodynamics. The aim of this study was to compare the hemodynamic performance of Freestyle (Medtronic) and Trifecta at rest and during exercise in patients with a small aortic annulus.
  
  
  METHODS
  From September 2012 to September 2014, 22 patients with a native aortic annulus ≤ 23 mm underwent ergometric stress testing one year after aortic valve replacement with either a Trifecta (12 patients) or a Freestyle (10 patients) bioprosthesis as part of a randomized study.
  
  
  RESULTS
  The mean gradient at rest was 6.0 ± 2.3 mmHg for Trifecta and 4.3 ± 3.5 for Freestyle (p = 0.213). The mean gradient at peak of exercise was 9.7 ± 3.4 mmHg for Trifecta and 7.4 ± 5 mmHg for Freestyle (p = 0.243). No significant differences were found between the two prostheses regarding other hemodynamic parameters: effective orifice area, velocity index, and performance indexes.
  
  
  CONCLUSIONS
  Both the stented Trifecta and stentless Freestyle prostheses provide excellent hemodynamic results during physical stress in patients with a small aortic annulus. Our study confirms that Trifecta implantation results in low gradients at rest and during exercise and that the performance of Trifecta is similar to that of a stentless valve.
authors.affiliation: Department of Cardiovascular, Operative Unit of Cardiac Surgery, Ospedale "A. Manzoni" di Lecco, Lecco, Italy; Department of Electronic, Information and Bioengeering, Politecnico di Milano, Milan, Italy.
authors.forename: Giordano
authors.initials: G
authors.lastname: Tasca
authors.forename: Paola
authors.initials: P
authors.lastname: Redaelli
authors.forename: Beatrice
authors.initials: B
authors.lastname: Riva
authors.forename: Caterina Chiara
authors.initials: CC
authors.lastname: De Carlini
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Lobiati
authors.forename: Amando
authors.initials: A
authors.lastname: Gamba
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000502:physiology* / Q000601:surgery; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D017063:Outcome Assessment, Health Care; D011474:Prosthesis Design