title: Are stentless valves hemodynamically superior to stented valves? A prospective randomized trial.
abstract: BACKGROUND
  Although stentless aortic bioprostheses are believed to offer improved outcomes, hemodynamic benefits remain unsubstantiated.
  
  
  METHODS
  Fifty-three patients were randomized to receive the stented C-E pericardial valve (CE) and 46 patients the Toronto Stentless Porcine valve (SPV). Annuli were sized for the optimal insertion of both valve types, such that surgeons were required to commit to specific valve sizes before randomization. Echocardiographic measurements and functional status (Duke Activity Status Index) were assessed at 3 and 12 months postoperatively.
  
  
  RESULTS
  Although cardiopulmonary bypass times (CE: 118.6+/-36.3 minutes; SPV: 148.5+/-30.9 minutes; p = 0.0001) and aortic cross-clamp times (CE: 95.4+/-28.6 minutes; SPV: 123.6+/-24.1 minutes; p = 0.0001) were significantly prolonged in the SPV group, perioperative morbidity and mortality was similar between groups. Neither valve offered a superior internal diameter for any given annular diameter (mean decrease in left ventricular outflow tract diameter after valvular implantation: SPV: 3.4+/-1.11 mm versus CE: 3.7+/-1.33 mm; p = 0.25). Although labeled mean valve size was significantly larger in the SPV group, the actual mean valve size based on internal valvular diameter was no different between groups (CE: 21.9+/-2.0 mm; SPV: 22.3+/-2.0 mm; p = 0.286). Although effective orifice areas increased, and mean and peak transvalvular gradients decreased in both groups over time, no differences were demonstrated between groups at 12 months. Similarly, although significant regression of left ventricular mass was accomplished in both groups over time, no differences were demonstrated between groups. Finally, Duke Activity Status Index scores of functional status improved in both groups over time; however, no differences were noted between groups at 12 months postoperatively.
  
  
  CONCLUSIONS
  Although offering excellent outcomes, stentless valves did not demonstrate superior hemodynamic indices in comparison to stented valves up to 12 months after implantation.
authors.affiliation: Division of Cardiovascular Surgery, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Ontario, Canada.
authors.forename: Gideon
authors.initials: G
authors.lastname: Cohen
authors.forename: George T
authors.initials: GT
authors.lastname: Christakis
authors.forename: Campbell D
authors.initials: CD
authors.lastname: Joyner
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Morgan
authors.forename: Miguel
authors.initials: M
authors.lastname: Tamariz
authors.forename: Naoji
authors.initials: N
authors.lastname: Hanayama
authors.forename: Hari
authors.initials: H
authors.lastname: Mallidi
authors.forename: J P
authors.initials: JP
authors.lastname: Szalai
authors.forename: Marko
authors.initials: M
authors.lastname: Katic
authors.forename: Vivek
authors.initials: V
authors.lastname: Rao
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Fremes
authors.forename: Bernard S
authors.initials: BS
authors.lastname: Goldman
mesh_terms: D000368:Aged; D001021:Aortic Valve; D001024:Aortic Valve Stenosis / Q000503:physiopathology / Q000601:surgery; D001705:Bioprosthesis; D005260:Female; D006350:Heart Valve Prosthesis; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D016277:Ventricular Function, Left