title: Valve replacement with the ATS open pivot bileaflet prosthesis.
abstract: OBJECTIVE
  We sought to evaluate the ATS open pivot bileaflet valve with respect to haemodynamics and thromboembolism.
  
  
  METHODS
  We prospectively studied 200 consecutive patients aged 13-80 years. One hundred and nineteen aortic, 103 mitral and 11 tricuspid valves were replaced in 172 single, 23 double and 5 triple valve procedures. Thirty-eight were re-operations and 51 underwent coronary bypass. Transvalvular gradients were determined by transoesophageal and transthoracic echocardiography. Patients were followed for 12 months to 3 years.
  
  
  RESULTS
  There were four hospital (2%) and three late deaths, each non-valve related. Two patients were reoperated for partial valve dehiscence. One aortic reoperation patient suffered a potential transient thromboembolic event. One tricuspid prosthesis thrombosed after anticoagulation was discontinued but thrombolysis resolved this problem. There were no other thromboembolic events. Valve gradients were equivalent or better than those for other bileaflet valves.
  
  
  CONCLUSIONS
  The ATS valve has excellent haemodynamic characteristics and a very low thromboembolic rate, probably related to the convex self-washing hinge mechanism. Consequently, we have reduced anticoagulant levels to INR (international normalised ratio) 1.5 to 2.0 for aortic valve patients in sinus rhythm. Early experience suggests that the ATS valve functions well in the tricuspid position.
authors.affiliation: Oxford Heart Centre, John Radeliffe Hospital, UK.
authors.forename: S
authors.initials: S
authors.lastname: Westaby
authors.forename: G
authors.initials: G
authors.lastname: Van Nooten
authors.forename: H
authors.initials: H
authors.lastname: Sharif
authors.forename: R
authors.initials: R
authors.lastname: Pillai
authors.forename: F
authors.initials: F
authors.lastname: Caes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery; D001705:Bioprosthesis; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D005260:Female; D006349:Heart Valve Diseases / Q000503:physiopathology / Q000601:surgery; D006350:Heart Valve Prosthesis / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery; D009017:Morbidity; D011183:Postoperative Complications / Q000503:physiopathology*; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D013923:Thromboembolism / Q000453:epidemiology / Q000209:etiology*; D014261:Tricuspid Valve / Q000601:surgery