title: Serum Ammonia is Associated With Transplant-free Survival in Hospitalized Patients With Acutely Decompensated Cirrhosis [corrected].
abstract: As ammonia metabolism is a complex multiorgan process, we sought to determine whether serum ammonia concentrations were associated with transplant-free survival in patients with acutely decompensated cirrhosis and acute-on-chronic liver failure (ACLF).
  
  
  
  We studied 494 consecutive patients hospitalized with cirrhosis between April 2007 and September 2012 with venous ammonia measured on hospital admission. The primary outcome was transplant-free survival.
  
  
  
  Overall, rates of death or transplant within 30 and 90 days were 23.1% (n=114) and 37.7% (n=186), respectively. Forty-six patients (9.2%) underwent liver transplantation within 90 days. In a multivariate Cox proportional hazards model, ammonia concentration was independently associated with death or transplantation within 30 and 90 days after adjusting for model for end-stage liver disease, sodium, white blood cells, and number of ACLF organ failures; every doubling of ammonia was associated with respective hazard ratios of 1.22 (95% confidence interval, 1.03-1.38) and 1.21 (95% confidence interval, 1.04-1.44) for 90- and 30-day transplant or mortality. Notably, after adjusting for ammonia, organ failures were not predictive of outcomes. In a Kaplan-Meier analysis, patients with admission ammonia concentrations >60 μmol/L had significantly lower 90-day transplant-free survival (P=0.0004). Patients with admission ammonia concentrations >60 μmol/L had higher 90- and 30-day risk of death or transplantation (45.2% vs. 31.2%, P=0.001; and 31.6% vs. 15.7%, P<0.0001, respectively).
  
  
  
  For patients with acutely decompensated cirrhosis, an elevated serum ammonia concentration on admission is associated with reduced 90-day transplant-free survival after adjusting for established predictors.
authors.affiliation: *Division of Gastroenterology†Department of Medicine‡Decision Support, Beth Israel Deaconess Medical Center, Boston, MA.
authors.forename: Vilas R
authors.initials: VR
authors.lastname: Patwardhan
authors.forename: Zhengui G
authors.initials: ZG
authors.lastname: Jiang
authors.forename: Yesenia
authors.initials: Y
authors.lastname: Risech-Neiman
authors.forename: Gail
authors.initials: G
authors.lastname: Piatkowski
authors.forename: Nezam H
authors.initials: NH
authors.lastname: Afdhal
authors.forename: Kenneth
authors.initials: K
authors.lastname: Mukamal
authors.forename: Michael P
authors.initials: MP
authors.lastname: Curry
authors.forename: Elliot B
authors.initials: EB
authors.lastname: Tapper
mesh_terms: D065290:Acute-On-Chronic Liver Failure / Q000097:blood* / Q000175:diagnosis / Q000401:mortality / Q000601:surgery; D000368:Aged; D000641:Ammonia / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008103:Liver Cirrhosis / Q000097:blood* / Q000175:diagnosis / Q000401:mortality / Q000601:surgery; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010343:Patient Admission; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D000641:Ammonia