title: Early clinical experience with the On-X prosthetic heart valve.
abstract: OBJECTIVE
  The study was designed to investigate the clinical performance of the On-X prosthetic heart valve in a multicenter experience.
  
  
  METHODS
  Between September 1996 and September 1999, 301 patients (56% males) underwent isolated On-X valve replacement (184 isolated aortic (AVR), 117 isolated mitral (MVR)) at 11 European centers under a standardized protocol. Average age at implant was 60.2 years. Office or hospital follow up was required by the protocol; average follow up on all patients was 11 months.
  
  
  RESULTS
  Thirty-day mortality in the study was 2.2% for AVR and 6.0% for MVR, with valve-related mortality of 0.5% for AVR. There were eight late deaths (0.7%/pt-yr AVR and 2.3%/pt-yr MVR). Two of these deaths were sudden, and thus possibly valve-related (one AVR, one MVR). Early total valve-related morbidity was 3.5% for AVR and 2.6% for MVR. In total, 13 thromboembolic events occurred; one early event in AVR resulted in death (0.5%), and one transient early event occurred in MVR (0.9%). There were 11 late events (seven AVR (1.7%/pt-yr) and four MVR (1.8%/pt-yr)), for a two-year freedom from thromboembolism of 96.6% after AVR and 97.1% after MVR. Three late bleeding events occurred, all after AVR (0.7%/pt-yr and 98.9% free at two years). Major paravalvular leaks requiring reoperation occurred on two occasions early (one AVR (0.5%), one MVR (0.8%)) and once late in MVR (0.5%/pt-yr). Late minor, untreated paravalvular leaks occurred in three AVR patients (0.7%/pt-yr) and in one MVR patient (0.5%/pt-yr). Prosthetic endocarditis occurred four times (two AVR (0.5%/pt-yr), two MVR (0.9%/pt-yr)), all within the first 12 months of surgery. Actuarial freedom from all valve-related events at two years was 88.7% for AVR and 88.1% for MVR. NYHA class was improved in 75.8% of AVR patients and 70.6% of MVR patients at two years after surgery.
  
  
  CONCLUSIONS
  These early results indicate that the On-X valve provides satisfactory clinical outcome in the immediate postoperative period, and that the valve is both safe and effective.
authors.affiliation: Universitätsklinikum Bergmannsheil, Bochum, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Laczkovics
authors.forename: M
authors.initials: M
authors.lastname: Heidt
authors.forename: H
authors.initials: H
authors.lastname: Oelert
authors.forename: G
authors.initials: G
authors.lastname: Laufer
authors.forename: H
authors.initials: H
authors.lastname: Greve
authors.forename: J L
authors.initials: JL
authors.lastname: Pomar
authors.forename: F W
authors.initials: FW
authors.lastname: Mohr
authors.forename: A
authors.initials: A
authors.lastname: Haverich
authors.forename: D
authors.initials: D
authors.lastname: Birnbaum
authors.forename: D
authors.initials: D
authors.lastname: Regensburger
authors.forename: G
authors.initials: G
authors.lastname: Palatianos
authors.forename: E
authors.initials: E
authors.lastname: Wolner
mesh_terms: D000206:Actuarial Analysis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery*; D002423:Cause of Death; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D011183:Postoperative Complications / Q000401:mortality; D011474:Prosthesis Design; D016019:Survival Analysis