title: Impact of initial Norwood shunt type on young hypoplastic left heart syndrome patients listed for heart transplant: A multi-institutional study.
abstract: BACKGROUND
  Pulmonary blood flow during Stage 1 (Norwood) palliation for hypoplastic left heart syndrome (HLHS) is achieved via modified Blalock-Taussig shunt (MBT) or right ventricle to pulmonary artery conduit (RVPA). Controversy exists regarding the differential impact of shunt type on outcome among those who require transplantation early in life. In this study we explored waitlist and post-transplant outcomes within this sub-population stratified by shunt type.
  
  
  METHODS
  Eligible patients were enrolled through the Pediatric Heart Transplant Study (PHTS) database. Patients included those listed for heart transplantation at 1 of 35 participating centers, all of whom were <6 years of age and with a diagnosis of HLHS (and variants) status post Stage 1 palliation with MBT or RVPA. Standard risk factors for death were analyzed using multivariable hazards modeling.
  
  
  RESULTS
  Between 2010 and 2013, 190 patients were identified. Compared with the RVPA group (n = 111), the MBT group (n = 79) was less likely to have undergone a Glenn palliation (41% vs 73%, p < 0.001), were younger at listing (median age 1.3 vs 1.8 years, p = 0.05), had lower median weight (7.9 vs 9.4 kg, p = 0.02), and were more likely to be mechanically ventilated at listing (35% vs 22%, p = 0.04). There were no significant differences in median waitlist time (1.7 vs 2.6 months, p = 0.2) or rate of transplantation (61% vs 60%, p = 1.0). Among waitlisted patients, 3-month survival was less for MBT compared with RVPA patients (74% vs 91%, p = 0.02). Patients who had not yet achieved Glenn palliation before listing had lower waitlist 3-month survival (76% vs 90%, p = 0.02). In MBT infants <1 year old, there was a trend toward improved survival in those with Glenn palliation compared to those without (100% vs 68%, p = 0.08). Early post-transplant mortality rates were similar between the RVPA and MBT groups (p = 0.4) with overall survival 84% at 1 year.
  
  
  CONCLUSIONS
  Among HLHS patients, the need for transplant before Glenn palliation is associated with poorer waitlist survival. Waitlist survival is poorer in the MBT group, with this difference driven by pre-Glenn MBT infants. Post-transplant outcomes were unaffected by shunt type.
authors.affiliation: Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama. Electronic address: wfcarlo@peds.uab.edu.
authors.forename: Waldemar F
authors.initials: WF
authors.lastname: Carlo
authors.affiliation: Pediatric Cardiology, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors.forename: Shawn C
authors.initials: SC
authors.lastname: West
authors.affiliation: Nemours Cardiac Center, Wilmington, Delaware.
authors.forename: Michael
authors.initials: M
authors.lastname: McCulloch
authors.affiliation: Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: David C
authors.initials: DC
authors.lastname: Naftel
authors.affiliation: Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Pruitt
authors.affiliation: Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: James K
authors.initials: JK
authors.lastname: Kirklin
authors.affiliation: Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: Meloneysa
authors.initials: M
authors.lastname: Hubbard
authors.affiliation: Section of Pediatric Cardiology, Primary Children's Hospital, Salt Lake City, Utah.
authors.forename: Kimberly M
authors.initials: KM
authors.lastname: Molina
authors.affiliation: The Heart Center, Nationwide Children's Hospital, Columbus, Ohio.
authors.forename: Robert
authors.initials: R
authors.lastname: Gajarski
mesh_terms: D005260:Female; D016027:Heart Transplantation; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000601:surgery*; D007223:Infant; D008297:Male; D058327:Norwood Procedures / Q000379:methods; D016896:Treatment Outcome; D014850:Waiting Lists
keywords: hypoplastic left heart syndrome; pediatric cardiac transplantation; single ventricle