title: Uric acid for diagnosis and risk stratification in suspected myocardial infarction.
abstract: BACKGROUND
  Hypoxia precedes cardiomyocyte necrosis in acute myocardial infarction (AMI). We therefore hypothesized that uric acid - as a marker of oxidative stress and hypoxia - might be useful in the early diagnosis and risk stratification of patients with suspected AMI.
  
  
  METHODS
  In this prospective observational study, uric acid was measured at presentation in 892 consecutive patients presenting to the emergency department with suspected AMI. The final diagnosis was adjudicated by two independent cardiologists. Patients were followed 24 months regarding mortality. Primary outcome was the diagnosis of AMI, secondary outcome was short- and long-term mortality.
  
  
  RESULTS
  Uric acid at presentation was higher in patients with AMI than in patients without (372 μM vs. 336 μM; P < 0·001). The diagnostic accuracy of uric acid for AMI as quantified by the area under the receiver operating characteristic curve (AUC) was 0·60 (95%Cl 0·56-0·65). When added to cardiac troponin T (cTnT), uric acid significantly increased the AUC of cTnT from 0·89 (95%Cl 0·85-0·93) to 0·92 (95%Cl 0·89-0·95, P = 0·020 for comparison). Cumulative 24-month mortality rates were 2·2% in the first, 5·4% in the second and the third and 15·6% in the fourth quartile of uric acid (P < 0·001 for log-rank). Uric acid predicted 24-month mortality independently. Adding uric acid to TIMI and GRACE risk score improved their prognostic accuracy as shown by an integrated discrimination improvement of 0·04 (P = 0·007) respective 0·02 (P = 0·021).
  
  
  CONCLUSIONS
  Uric acid, an inexpensive widely available biomarker, improves both the early diagnosis and risk stratification of patients with suspected AMI.
authors.affiliation: Department of Cardiology, University Hospital, CH-4031 Basel, Switzerland.
authors.forename: Karin
authors.initials: K
authors.lastname: Wildi
authors.forename: Philip
authors.initials: P
authors.lastname: Haaf
authors.forename: Tobias
authors.initials: T
authors.lastname: Reichlin
authors.forename: Resat
authors.initials: R
authors.lastname: Acemoglu
authors.forename: Jeannine
authors.initials: J
authors.lastname: Schneider
authors.forename: Cathrin
authors.initials: C
authors.lastname: Balmelli
authors.forename: Beatrice
authors.initials: B
authors.lastname: Drexler
authors.forename: Raphael
authors.initials: R
authors.lastname: Twerenbold
authors.forename: Tamina
authors.initials: T
authors.lastname: Mosimann
authors.forename: Miriam
authors.initials: M
authors.lastname: Reiter
authors.forename: Mira
authors.initials: M
authors.lastname: Mueller
authors.forename: Susanne
authors.initials: S
authors.lastname: Ernst
authors.forename: Paola
authors.initials: P
authors.lastname: Ballarino
authors.forename: Christa
authors.initials: C
authors.lastname: Zellweger
authors.forename: Berit
authors.initials: B
authors.lastname: Moehring
authors.forename: Carles
authors.initials: C
authors.lastname: Vilaplana
authors.forename: Heike
authors.initials: H
authors.lastname: Freidank
authors.forename: Christian
authors.initials: C
authors.lastname: Mueller
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood*; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis* / Q000401:mortality; D018384:Oxidative Stress; D011237:Predictive Value of Tests; D012307:Risk Factors; D014527:Uric Acid / Q000097:blood*
chemical_list: D015415:Biomarkers; D014527:Uric Acid