title: Living at altitude adversely affects survival among patients with a Fontan procedure.
abstract: OBJECTIVE
  This study sought to determine whether survival in this cohort of patients was adversely affected by increased residential altitude.
  
  
  BACKGROUND
  The success of the Fontan procedure depends in large part on low pulmonary vascular resistance (PVR). Factors that increase PVR, including an increase in residential altitude, may adversely affect long-term outcome. Higher altitude has been shown to affect functional well-being in patients with a Fontan circulation.
  
  
  METHODS
  Databases from a tertiary cardiac care center in the Intermountain West (elevation 5,000 feet) were analyzed for patients born with single-ventricle anatomy who would now be of adult age. Complete data were then collected on all identified patients who subsequently underwent the Fontan operation. Correlates of, and time to, adverse outcome, defined as death, cardiac transplantation, or clinical decompensation requiring a move to sea level, were determined.
  
  
  RESULTS
  Of 149 patients with single-ventricle anatomy, 103 underwent the Fontan procedure, with 70 surviving to adulthood at moderate altitude. Adverse outcome occurred in 55, with death in 24 (23%), cardiac transplantation in 18 (17%), and clinical decompensation requiring move to sea level in 13 (13%). There was no relationship between type, age at, or era of Fontan procedure and long-term outcome. Correlates of long-term, transplant-free survival at moderate altitude included lower residential altitude (4,296 vs. 4,637 feet, p < 0.001), and lower pulmonary artery pressures before the Fontan procedure (13 vs. 15 mm Hg, p = 0.01), and after (14 vs. 18 mm Hg, p = 0.01).
  
  
  CONCLUSIONS
  Long-term outcome after the Fontan procedure is adversely impacted by higher residential altitude.
authors: Division of Cardiology, Department of Pediatrics, Primary Children's Medical Center, University of Utah, Salt Lake City, Utah 84113, USA.
authors: Joy T
authors: JT
authors: Johnson
authors: Ian
authors: I
authors: Lindsay
authors: Ronald W
authors: RW
authors: Day
authors: Charlotte S
authors: CS
authors: Van Dorn
authors: James
authors: J
authors: Hoffman
authors: Melanie D
authors: MD
authors: Everitt
authors: Anji T
authors: AT
authors: Yetman
mesh_terms: D000293:Adolescent; D000328:Adult; D000532:Altitude Sickness / Q000401:mortality* / Q000503:physiopathology; D002423:Cause of Death; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D018729:Fontan Procedure / Q000401:mortality*; D016027:Heart Transplantation / Q000401:mortality; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D010100:Oxygen / Q000097:blood; D011157:Population Dynamics; D011183:Postoperative Complications / Q000401:mortality* / Q000503:physiopathology; D012307:Risk Factors; D013223:Statistics as Topic; D015996:Survival Rate; D014655:Vascular Resistance / Q000502:physiology; D055815:Young Adult
chemical_list: D010100:Oxygen