title: Survival and right ventricular performance for matched children after stage-1 Norwood: Modified Blalock-Taussig shunt versus right-ventricle-to-pulmonary-artery conduit.
abstract: OBJECTIVE
  Early survival advantages after Norwood with right-ventricle-(RV)-to-pulmonary-artery conduit (NW-RVPA) over Norwood-operation with a Blalock-Taussig shunt (NW-BT) are offset by concerns regarding delayed RV dysfunction. We compared trends in survival, RV dysfunction, and tricuspid valve regurgitation (TR) between NW-RVPA and NW-BT for propensity-matched neonates with critical left ventricular outflow tract obstruction (LVOTO).
  
  
  METHODS
  In an inception cohort (2005-2014; 21 institutions), 454 neonates with critical LVOTO underwent Norwood stage 1. Propensity-score matching paired 169 NW-RVPA patients with 169 NW-BT patients. End-states were compared between NW-RVPA and NW-BT using competing-risks, multiphase, parametric, hazard analysis. Post-Norwood echocardiogram reports (n = 2993) were used to grade RV dysfunction and TR. Time-related prevalence of ≥moderate RV dysfunction and TR were characterized using nonlinear mixed-model regression, and compared between groups via multiphase, parametric models.
  
  
  RESULTS
  Overall 6-year survival was better after NW-RVPA (70%) versus NW-BT (55%; P < .001). Additionally, transplant-free survival during this time was better after NW-RVPA (64%) versus NW-BT (53%; P = .004). Overall prevalence of ≥moderate RV dysfunction reached 11% within 3 months post-Norwood. During this time, RV dysfunction after NW-BT was 16% versus 6% after NW-RVPA (P = .02), and coincided temporally with an increased early hazard for death. For survivors, late RV dysfunction was <5% and was not different between groups (P = .36). Overall prevalence of ≥moderate TR reached 13% at 2 years post-Norwood and was increased after NW-BT (16%) versus NW-RVPA (11%; P = .003). Late TR was similar between groups.
  
  
  CONCLUSIONS
  Among propensity-score-matched neonates with critical LVOTO, NW-RVPA offers superior 6-year survival with no greater prevalence of RV dysfunction or TR than conventional NW-BT operations.
authors.affiliation: Congenital Heart Surgeons' Society Data Center, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Travis J
authors.initials: TJ
authors.lastname: Wilder
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, University of Toronto, and The Hospital for Sick Children, Toronto, Canada.
authors.forename: Brian W
authors.initials: BW
authors.lastname: McCrindle
authors.affiliation: Department of Surgery, Division of Cardiothoracic Surgery, Cedars-Sinai Medical Center, Los Angeles, Calif.
authors.forename: Alistair B
authors.initials: AB
authors.lastname: Phillips
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Blackstone
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Jeevanantham
authors.initials: J
authors.lastname: Rajeswaran
authors.affiliation: Congenital Heart Surgeons' Society Data Center, The Hospital for Sick Children, Toronto, Canada.
authors.forename: William G
authors.initials: WG
authors.lastname: Williams
authors.affiliation: Department of Cardiothoracic Surgery, Arnold Palmer Hospital for Children, Orlando, Fla.
authors.forename: William M
authors.initials: WM
authors.lastname: DeCampli
authors.affiliation: Division of Cardiac Surgery, Department of Surgery, All Children's Hospital, Johns Hopkins University School of Medicine, Baltimore, Md.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Jacobs
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Md.
authors.forename: Marshall L
authors.initials: ML
authors.lastname: Jacobs
authors.affiliation: Division of Pediatric Cardiac Surgery, Benioff Children's Hospital, University of California San Francisco, San Francisco, Calif.
authors.forename: Tara
authors.initials: T
authors.lastname: Karamlou
authors.affiliation: Division of Cardiothoracic Surgery, Connecticut Children's Medical Center, Hartford; and Yale-New Haven Children's Hospital, New Haven, Conn.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Kirshbom
authors.affiliation: University of Missouri-Kansas City, Kansas City, Mo.
authors.forename: Gary K
authors.initials: GK
authors.lastname: Lofland
authors.affiliation: Department of Surgery, Division of Cardiac & Thoracic Surgery, University of Chicago School of Medicine, Chicago, Ill.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Ziemer
authors.affiliation: Department of Cardiovascular Surgery, University of Toronto, and The Hospital for Sick Children, Toronto, Ontario, Canada. Electronic address: edward.hickey@sickkids.ca.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Hickey
mesh_terms: D058366:Blalock-Taussig Procedure / Q000401:mortality; D002648:Child; D002675:Child, Preschool; D005260:Female; D006352:Heart Ventricles / Q000601:surgery*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D058327:Norwood Procedures / Q000401:mortality; D011651:Pulmonary Artery / Q000601:surgery*; D014262:Tricuspid Valve Insufficiency / Q000209:etiology; D016276:Ventricular Function / Q000502:physiology*; D014694:Ventricular Outflow Obstruction / Q000601:surgery
keywords: Norwood operation; congenital heart disease; critical left ventricular outflow tract obstruction; hypoplastic left heart syndrome; single ventricle