title: Mild residual pulmonary stenosis in tetralogy of fallot reduces risk of pulmonary valve replacement.
abstract: BACKGROUND
  Current surgical strategies that aim at preventing pulmonary regurgitation in patients with corrected tetralogy of Fallot (cToF) may result in a certain grade of residual pulmonary stenosis (PS). The clinical implications of a postoperative residual PS in cToF patients remain unclear. Pulmonary valve replacement (PVR) is frequently needed during follow-up of cToF patients. The aim of the current study was to determine the role of residual PS in the need for PVR during follow-up in cToF patients.
  
  
  METHODS
  cToF patients were included if clinical follow-up after primary surgical correction had taken place for a minimum of 5 years. Patient characteristics, surgical factors, and postoperative factors were reviewed, with a special focus on the transpulmonic systolic gradient. Cox proportional hazards regression analysis was performed to identify predictors of PVR.
  
  
  RESULTS
  Of 171 cToF patients, 71 (41.5%) underwent PVR after 24.2 years (interquartile range, 16.8-31.6 years). Year of birth, older age at corrective operation, and patch use significantly predicted PVR during follow-up. By contrast, a mild residual PS in cToF patients (peak systolic gradient, 15-30 mm Hg) independently reduced the risk of PVR, as compared with patients without PS (hazard ratio, 0.47; p=0.02) and with moderate-to-severe PS (hazard ratio, 0.35; p=0.01).
  
  
  CONCLUSIONS
  In addition to the known risks factors for PVR, a postoperative mild residual PS reduces the risk of PVR during follow-up of cToF patients. This finding provides clinical evidence for a conservative PS relief during correction of ToF.
authors.affiliation: Department of Pediatric Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Annelies E
authors.initials: AE
authors.lastname: van der Hulst
authors.forename: Marije G
authors.initials: MG
authors.lastname: Hylkema
authors.forename: Hubert W
authors.initials: HW
authors.lastname: Vliegen
authors.forename: Victoria
authors.initials: V
authors.lastname: Delgado
authors.forename: Mark G
authors.initials: MG
authors.lastname: Hazekamp
authors.forename: Marry E B
authors.initials: ME
authors.lastname: Rijlaarsdam
authors.forename: Eduard R
authors.initials: ER
authors.lastname: Holman
authors.forename: Nico A
authors.initials: NA
authors.lastname: Blom
authors.forename: Arno A W
authors.initials: AA
authors.lastname: Roest
mesh_terms: D000293:Adolescent; D000328:Adult; D006348:Cardiac Surgical Procedures / Q000379:methods*; D000075202:Contraindications; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D011379:Prognosis; D011666:Pulmonary Valve Stenosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000517:prevention & control; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013771:Tetralogy of Fallot / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016278:Ventricular Function, Right / Q000502:physiology*; D055815:Young Adult