title: Twenty-five-year experience with the Medtronic-Hall valve prosthesis in the aortic position: a follow-up cohort study of 816 consecutive patients.
abstract: BACKGROUND
  The Medtronic-Hall valve was developed and for the first time implanted in Oslo, Norway, in 1977. A total of 1104 patients received this valve at Rikshospitalet from 1977 to 1987. In the present study, we followed up on all 816 patients undergoing aortic valve replacement over a 25-year period.
  
  
  RESULTS
  This is a retrospective cohort analysis of 816 consecutive patients undergoing aortic valve replacement with the Medtronic-Hall valve at Rikshospitalet, Oslo, Norway, from 1977 to 1987. All patients were contacted by means of questionnaires or telephone. Data were checked against hospital databases and medical records. Date of death was verified by the Norwegian civil registry. Follow-up was 99.6% complete. Survival analysis included operative deaths as well as late deaths. Survival at 25 years was 24.9%. No mechanical failures were found. Valve thrombosis was seen in 4 patients, in 1 case combined with pannus formation. Small valves (20 mm to 21 mm) were associated with reduced survival; however, when controlled for the confounding effects of age and gender, valve size did not remain a significant risk factor. Patient-related factors were important: Older age, female gender, and the need for concomitant coronary artery bypass surgery significantly reduced survival, whereas surgery of the ascending aorta did not. Linearized rates of thromboembolic complications, warfarin-related bleeding, and endocarditis were 1.5%, 0.7%, and 0.16%/patient-year, respectively. At follow-up, 79% of the patients were in New York Heart Association classes I to II.
  
  
  CONCLUSIONS
  This study confirms the excellent long-term outcome for patients with Medtronic-Hall valves in the aortic position.
authors: Department of Thoracic and Cardiovascular Surgery, Rikshospitalet-Radiumhospitalet Medical Center, University of Oslo, 0027 Oslo, Norway. j.l.svennevig@medisin.uio.no
authors: Jan L
authors: JL
authors: Svennevig
authors: Michel
authors: M
authors: Abdelnoor
authors: Sigurd
authors: S
authors: Nitter-Hauge
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D001024:Aortic Valve Stenosis / Q000401:mortality* / Q000601:surgery*; D002648:Child; D001026:Coronary Artery Bypass / Q000401:mortality; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D011183:Postoperative Complications / Q000401:mortality; D012189:Retrospective Studies; D017678:Sex Distribution; D016019:Survival Analysis; D013997:Time Factors