title: Raised serum cardiac troponin I concentrations predict hospital mortality in intensive care unit patients.
abstract: BACKGROUND
  Recent work suggests that increased plasma concentrations of cardiac troponin I (cTnI) are common in critically ill patients and are associated with poor outcome. We measured the frequency of increased plasma cTnI concentrations during patients' stay in a mixed medical/surgical intensive care unit (ICU) and compared our findings with hospital mortality.
  
  
  METHODS
  Basic details, organ support, and hospital mortality were recorded for all patients treated in ICU during a 6 month period. cTnI concentrations were sampled daily for all patients, using 0.04 µg litre(-1) as the upper limit of normal, and 0.12 µg litre(-1) as an additional stratification point.
  
  
  RESULTS
  Of 663 patients, 54% were male, with a mean (sd) age of 60 (18) yr, 65% were surgical patients, and the median Acute Physiology and Chronic Ill Health II (APACHE II) score was 15 (inter-quartile range 12-20). Increased cTnI concentrations were found in 345 patients (52%) while in ICU. One hundred and twenty patients (18%) died in hospital. cTnI concentration >0.04 µg litre(-1) was associated with reduced odds of hospital survival, independent of age, medical admission, unplanned admission, APACHE II score, mechanical ventilation, and haemofiltration (adjusted odds ratio 0.25, 95% confidence interval 0.08-0.75, P=0.014). Stratification by the degree of cTnI increase revealed an incremental trend towards a lower odds of hospital survival, including for patients with 'minor' elevations of cTnI (0.05-0.12 µg litre(-1)).
  
  
  CONCLUSIONS
  Increased serum cTnI concentrations during ICU stay independently predicts hospital mortality, even when the threshold is low. We found a trend towards an association between 'minor' elevations in cTnI and higher in-hospital mortality.
authors.affiliation: General Intensive Care Unit, St George’s Hospital, London SW17 0RE, UK. toby.reynolds@gmail.com
authors.forename: T
authors.initials: T
authors.lastname: Reynolds
authors.forename: M
authors.initials: M
authors.lastname: Cecconi
authors.forename: P
authors.initials: P
authors.lastname: Collinson
authors.forename: A
authors.initials: A
authors.lastname: Rhodes
authors.forename: R M
authors.initials: RM
authors.lastname: Grounds
authors.forename: M A
authors.initials: MA
authors.lastname: Hamilton
mesh_terms: D018806:APACHE; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003422:Critical Care / Q000379:methods; D016638:Critical Illness / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay / Q000706:statistics & numerical data; D008131:London / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood / Q000401:mortality; D011379:Prognosis; D019210:Troponin I / Q000097:blood*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D019210:Troponin I