title: Performance of cavopulmonary palliation at elevated altitude: midterm outcomes and risk factors for failure.
abstract: BACKGROUND
  Outcomes of patients undergoing cavopulmonary palliation for single ventricle physiology may be impacted by living at altitude, as the passive pulmonary circulation is dependent on the resistance of the pulmonary vascular bed. The objective of this study is to identify risk factors for failure of cavopulmonary palliation at elevated altitude.
  
  
  RESULTS
  Between January 1995 and March 2007, 122 consecutive patients living at a mean altitude of 1600 m (range 305 to 2570) underwent a bidirectional Glenn (BDG). There was one in-hospital mortality and 7 late deaths. 52 have proceeded to the Fontan procedure. Survival after BDG was 92.4% at 5 years. Freedom from palliation failure, defined as death, transplant, BDG/Fontan takedown, or revision was 81% at 5 years. At a mean follow-up of 39.8 months, 90 patients (75%) were in New York Heart Association class I. Patients with failing cavopulmonary circulation had higher pre-BDG pulmonary artery pressure (PAP) (18.3+/-6.1 mm Hg versus 14.8+/-5.1 mm Hg, P=0.016) and higher pre-BDG transpulmonary gradient (TPG) (11.2+/-6.2 mm Hg versus 7.7+/-4.3 mm Hg, P=0.014). Post-BDG, patients with palliation failure had increased PAP (15.0+/-5.7 mm Hg versus 10.8+/-2.8 mm Hg, P=0.008) and indexed pulmonary vascular resistance (PVRI) (2.43+/-1.0 Wood U . m(2) versus 1.52+/-0.9 Wood U . m(2), P=0.007).
  
  
  CONCLUSIONS
  The majority of patients at moderate altitude have favorable outcomes after BDG or Fontan palliation. Risk factors for palliation failure at elevated altitude include PAP >15 mm Hg, TPG >8 mm Hg, and PVRI >2.5 Wood U . m(2).
authors.affiliation: Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA. spmalhotramd@yahoo.com
authors.forename: Sunil P
authors.initials: SP
authors.lastname: Malhotra
authors.forename: D Dunbar
authors.initials: DD
authors.lastname: Ivy
authors.forename: Max B
authors.initials: MB
authors.lastname: Mitchell
authors.forename: David N
authors.initials: DN
authors.lastname: Campbell
authors.forename: Marshall L
authors.initials: ML
authors.lastname: Dines
authors.forename: Shelley
authors.initials: S
authors.lastname: Miyamoto
authors.forename: Joseph
authors.initials: J
authors.lastname: Kay
authors.forename: David R
authors.initials: DR
authors.lastname: Clarke
authors.forename: Francois
authors.initials: F
authors.lastname: Lacour-Gayet
mesh_terms: D000531:Altitude; D000714:Anastomosis, Surgical; D006328:Cardiac Catheterization; D002315:Cardiopulmonary Bypass / Q000009:adverse effects / Q000379:methods / Q000401:mortality; D002648:Child; D002675:Child, Preschool; D018729:Fontan Procedure; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000601:surgery*; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000601:surgery; D007223:Infant; D007902:Length of Stay; D011652:Pulmonary Circulation; D012189:Retrospective Studies; D012307:Risk Factors; D017211:Treatment Failure; D016896:Treatment Outcome; D018785:Tricuspid Atresia / Q000601:surgery; D014683:Vena Cava, Superior; D014684:Venae Cavae / Q000503:physiopathology