title: Percutaneous pulmonary valve replacement after different duration of free pulmonary regurgitation in a porcine model: effects on the right ventricle.
abstract: BACKGROUND
  Free pulmonary regurgitation (PR) after surgical correction of Tetralogy of Fallot (ToF) with transannular patching can lead to irreversible right ventricular (RV) failure. However, the optimal timing of valve replacement is still debated.
  
  
  RESULTS
  Thirty six pigs were included in the study. Twenty one pigs had a bare metal stent placed in the pulmonary annulus inducing free PR and 9 animals served as control. Six animals died prematurely due to procedural complications. The 21 animals were divided into 3 groups with differential duration of PR (1, 2, 3 months, respectively) after which PPVR was performed. After 1 month with competent valve the animals were euthanized. Cardiac magnetic resonance (CMR) and right heart catheterization were performed serially. Free PR led to severe dilation of the RV in all three groups compared to matched controls (p<0.001). Final RV volume after one month with competent pulmonary valve was modeled. Increase in RV volume from baseline to valve replacement (ΔRV) was the only predictor of RV recovery (p<0.001) and increases in ΔRV beyond 120 mL/m2 were predictive of very low probability of recovery. A total of 5 animals did not recover.
  
  
  CONCLUSIONS
  Recovery of right ventricular function after free PR by treatment with PPVR was successful in the majority of animals. Increases in RV volume during PR were the only predictor of non-recovery after PPVR and duration of PR did not in itself predict treatment success.
authors.affiliation: The Heart Centre, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark. mads.ersboell@gmail.com
authors.forename: Mads
authors.initials: M
authors.lastname: Ersboell
authors.forename: Niels
authors.initials: N
authors.lastname: Vejlstrup
authors.forename: Jens Christian
authors.initials: JC
authors.lastname: Nilsson
authors.forename: Jesper
authors.initials: J
authors.lastname: Kjaergaard
authors.forename: Wendy
authors.initials: W
authors.lastname: Norman
authors.forename: Theis
authors.initials: T
authors.lastname: Lange
authors.forename: Andrew
authors.initials: A
authors.lastname: Taylor
authors.forename: Philipp
authors.initials: P
authors.lastname: Bonhoeffer
authors.forename: Lars
authors.initials: L
authors.lastname: Sondergaard
mesh_terms: D000818:Animals; D006328:Cardiac Catheterization / Q000379:methods*; D004195:Disease Models, Animal; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D011664:Pulmonary Valve / Q000473:pathology / Q000502:physiology / Q000601:surgery; D011665:Pulmonary Valve Insufficiency / Q000503:physiopathology / Q000601:surgery*; D013552:Swine; D016896:Treatment Outcome; D016278:Ventricular Function, Right / Q000502:physiology*