title: Single-center experience with the On-X prosthetic heart valve between 1996 and 2005.
abstract: OBJECTIVE
  Herein are presented long-term results for the On-X mechanical heart valve. All On-X heart valve recipients since the first implantation worldwide at the University of Bochum in September 1996 were followed retrospectively; the present authors' single-center experience over a period of almost 10 years is reported.
  
  
  METHODS
  A total of 428 patients (255 males, 173 females; mean age 62.7 years) underwent either aortic valve replacement (AVR; n = 264) or mitral valve replacement (MVR; n = 164) using the On-X prosthesis. Preoperatively, 329 patients (76.8%) were in NYHA class III or IV. Approximately 5% of AVR and 23% of MVR patients had undergone previous cardiac surgery. Concomitant surgery was performed in 189 patients (44.2%). The mean follow up was 3.9 years, and cumulative follow up 1,625 patient-years (pt-yr); the overall follow up rate was 98.7%.
  
  
  RESULTS
  Early mortality (< or = 30 days) was 3.7% after AVR and 14.0% after MVR, with valve-related mortality rates of 0.4% and 1.2%, respectively. At autopsy (n = 12) all implants were intact. Freedom from valve-related death at nine years was 85.0 +/- 3.9% after AVR and 87.6 +/- 3.2% after MVR. The overall survival rate was 67.9 +/- 4.3% after AVR and 52.7 +/- 8.1% after MVR. The linearized rate of thromboembolism for AVR and MVR was 1.49%/pt-yr and 1.61%/pt-yr; of thrombosis 0%/pt-yr and 0.35%/pt-yr; of hemorrhage 0.93%/pt-yr and 1.43%/pt-yr; of endocarditis 0.37%/pt-yr and 0.17%/pt-yr; of non-structural failure 0.18%/pt-yr and 1.43%/pt-yr; and of reoperation 0.28%/pt-yr and 0.53%/pt-yr. There were no cases of structural valve failure.
  
  
  CONCLUSIONS
  After almost one decade of clinical experience in a single center, the On-X heart valve continues to be reliable and effective.
authors.affiliation: Department of Cardiothoracic Surgery, BG Universitätsklinikum Bergmannsheil, University of Bochum, Bochum, Germany. ptossios@hotmail.com
authors.forename: Paschalis
authors.initials: P
authors.lastname: Tossios
authors.forename: Delawer
authors.initials: D
authors.lastname: Reber
authors.forename: Maria
authors.initials: M
authors.lastname: Oustria
authors.forename: Tim
authors.initials: T
authors.lastname: Holland-Letz
authors.forename: Alfried
authors.initials: A
authors.lastname: Germing
authors.forename: Dirk
authors.initials: D
authors.lastname: Buchwald
authors.forename: Axel
authors.initials: A
authors.lastname: Laczkovics
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery*; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D005858:Germany; D006349:Heart Valve Diseases / Q000601:surgery*; D006350:Heart Valve Prosthesis / Q000009:adverse effects; D019918:Heart Valve Prosthesis Implantation / Q000379:methods; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D012189:Retrospective Studies; D015996:Survival Rate; D013923:Thromboembolism / Q000209:etiology / Q000401:mortality