title: Mid-term outcome of mechanical pulmonary valve prostheses: the importance of anticoagulation.
abstract: BACKGROUND
  Pulmonary valve replacement (PVR) is being performed more commonly late after the correction of tetralogy of Fallot. Most valves are replaced with an allograft or xenograft, although reoperations are a common theme. Mechanical prostheses have a less favorable reputation due to the necessity of lifelong anticoagulation therapy and higher risk of thrombosis, but they are also less likely to require reoperation. There is a paucity of data on the use of prosthetic valves in the pulmonary position. We report the midterm outcomes of 38 cases of PVR with mechanical prostheses.
  
  
  METHODS
  One hundred twenty two patients who underwent PVR were studied. Thirty-eight patients, mean age 25 ± 8.4 years underwent PVR with mechanical prostheses based on the right ventricular function and the preferences of the patients and physicians. Median age of prosthesis was 1 year (range 3 months to 5 years).
  
  
  RESULTS
  Seven (18%) patients had malfunctioning pulmonary prostheses and two patients underwent redo PVR. Mean International Normalized Ratio (INR) in these seven patients was 2.1±0.8. Fibrinolytic therapy was tried and five of them responded to it well. There was no significant association between the severity of right ventricular dysfunction, patient's age, prostheses valve size and age of the prosthesis in the patients with prosthesis malfunction.
  
  
  CONCLUSIONS
  PVR with mechanical prostheses can be performed with promising midterm outcomes. Thrombosis on mechanical pulmonary valve prostheses remains a serious complication, but most prosthesis malfunction respond to fibrinolytic therapy, underscoring the need for adequate anticoagulation therapy.
authors.affiliation: Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Anita
authors.initials: A
authors.lastname: Sadeghpour
authors.affiliation: Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Kyavar
authors.affiliation: Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Bahareh
authors.initials: B
authors.lastname: Javani
authors.affiliation: Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Hooman
authors.initials: H
authors.lastname: Bakhshandeh
authors.affiliation: Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Maleki
authors.affiliation: Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Khajali
authors.affiliation: Section of Cardiology, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Lakshman
authors.initials: L
authors.lastname: Subrahmanyan
keywords: Anticogulation; Mechanical Prosthese; Plumonary Valve Replacement; Warfarin