title: Comparison of On-X and SJM HP bileaflet aortic valves.
abstract: OBJECTIVE
  The study aim was to evaluate the hemodynamic function after aortic valve replacement (AVR) using the On-X valve, in comparison with St. Jude Medical (SJM) HP bileaflet valves.
  
  
  METHODS
  Patients received either the On-X (n = 20) or SJM HP prosthesis (n = 20) for AVR. The control (SJM HP) group was computer-matched with the On-X group for age, gender, aortic stenosis as underlying disease, body surface area, NYHA functional class, left ventricular size, mass and function, transvalvular pressure gradients and cardiac index. Mean implanted valve size was 23.5 mm (three 21 mm, ten 23 mm, six 25 mm, one 27 mm) in both groups. All patients underwent postoperative, and six- and 12-month follow up echocardiography.
  
  
  RESULTS
  The intra- and postoperative course was uneventful in all patients. There were no significant differences in cross-clamp and cardiopulmonary bypass times, intensive care unit stay, in-hospital stay and postoperative NYHA functional class. Two patients (both On-X) had paravalvular leakage postoperatively and at follow up. Five patients in the control group had additional myocardial revascularization. Transvalvular flow velocities were 2.38 +/- 0.3 versus 2.38 +/- 0.4 m/s (p = NS) postoperatively, and 2.08 +/- 0.2 versus 2.22 +/- 0.3 m/s (p = NS) at one year follow up for On-X and SJM HP valves, respectively. Maximum pressure gradients were 16.9 +/- 6.0 versus 18.5 +/- 8.0 mmHg (p = NS) postoperatively and 14.0 +/- 3.7 versus 16.5 +/- 5.7 mmHg (p = NS) at one year for the two valve types, respectively. A relatively pronounced transvalvular reflux was diagnosed for On-X valves.
  
  
  CONCLUSIONS
  At one year after implantation, the On-X bileaflet prosthesis is equally suited for AVR in comparison with the 'standard' therapy (SJM HP). Exact sizing requires some experience. There were no significant differences between the two prostheses with regard to hemodynamic parameters either postoperatively or at one-year follow up. Long-term prospective randomized studies yet have to be carried out.
authors.affiliation: Department of Cardiac Surgery, Heart Center, University of Leipzig, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Walther
authors.forename: V
authors.initials: V
authors.lastname: Falk
authors.forename: R
authors.initials: R
authors.lastname: Tigges
authors.forename: M
authors.initials: M
authors.lastname: Krüger
authors.forename: G
authors.initials: G
authors.lastname: Langebartels
authors.forename: A
authors.initials: A
authors.lastname: Diegeler
authors.forename: R
authors.initials: R
authors.lastname: Autschbach
authors.forename: F W
authors.initials: FW
authors.lastname: Mohr
mesh_terms: D001021:Aortic Valve; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000601:surgery*; D015150:Echocardiography, Doppler; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D017755:Prosthesis Fitting; D013997:Time Factors