title: Percutaneous pulmonary valve implantation in the young 2-year follow-up.
abstract: OBJECTIVE
  The aim of this study was to investigate physiological and clinical consequences of percutaneous pulmonary valve implantation (PPVI) in patients with chronic right ventricular outflow tract (RVOT) obstruction and volume overload.
  
  
  BACKGROUND
  The PPVI is a nonsurgical technique to address RVOT conduit dysfunction.
  
  
  METHODS
  Twenty-eight adolescents (median age 14.9 years; age range 10.9 to 19 years) underwent PPVI due to RVOT stenosis and/or pulmonary regurgitation (PR). Before and after PPVI echocardiographic and magnetic resonance imaging, cardiopulmonary exercise tests were obtained.
  
  
  RESULTS
  The RVOT gradient (p < 0.001) and right ventricular (RV) systolic pressure decreased (p < 0.001), acutely. Magnetic resonance imaging (median 6 months) documented reduction in RV end-diastolic (149 +/- 49 ml/m(2) vs. 114 +/- 35 ml/m(2), p < 0.005) volume, increases in left ventricular (LV) end-diastolic (p < 0.007) volume and cardiac output (RV: p < 0.04 and LV: p < 0.02), and reduced PR fraction (24 +/- 10% to 7 +/- 7%, p < 0.0001). Symptoms, aerobic exercise performance (maximal oxygen consumption: p < 0.0001) and ventilatory response to carbon dioxide production (p < 0.003) improved. After 24 months, echocardiography demonstrated the RV/systemic-pressure ratio, and RVOT peak pressure gradient reductions persisted, and PR was absent in 93% (n = 12 of 13) of the cohort. Freedom from surgery was 91%, 83%, and 83%, and freedom from transcatheter reintervention was 91%, 80%, and 80%, at 12, 24, and 36 months, respectively. There were no acute device-related complications, with stent fractures noted in 10.8%.
  
  
  CONCLUSIONS
  Percutaneous pulmonary valve implantation is feasible and safe in the young with dysfunctional RVOT conduits. An improvement in symptoms, hemodynamic status, and objective findings of exercise performance occurs. Early follow-up demonstrates persistent improvement in ventricular parameters, PR, and objective exercise capacity.
authors.affiliation: Department of Pediatrics, The Hospital for Sick Children, The Labatt Family Heart Centre, University of Toronto School of Medicine, Toronto, Canada.
authors.forename: Marko
authors.initials: M
authors.lastname: Vezmar
authors.forename: Rajiv
authors.initials: R
authors.lastname: Chaturvedi
authors.forename: Kyong-Jin
authors.initials: KJ
authors.lastname: Lee
authors.forename: Claudia
authors.initials: C
authors.lastname: Almeida
authors.forename: Cedric
authors.initials: C
authors.lastname: Manlhiot
authors.forename: Brian W
authors.initials: BW
authors.lastname: McCrindle
authors.forename: Eric M
authors.initials: EM
authors.lastname: Horlick
authors.forename: Lee N
authors.initials: LN
authors.lastname: Benson
mesh_terms: D000293:Adolescent; D006328:Cardiac Catheterization / Q000295:instrumentation; D002404:Catheterization / Q000295:instrumentation; D002648:Child; D018618:Echocardiography, Doppler, Color; D005080:Exercise Test; D017079:Exercise Tolerance; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation / Q000379:methods*; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011665:Pulmonary Valve Insufficiency / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D020127:Recovery of Function; D015656:Respiratory Mechanics; D013997:Time Factors; D016896:Treatment Outcome; D016278:Ventricular Function, Right; D014694:Ventricular Outflow Obstruction / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D055815:Young Adult