title: Estimation of age- and comorbidities-adjusted percentiles of high-sensitivity cardiac troponin T levels in the elderly.
abstract: BACKGROUND
  Cardiac troponin level measured by high-sensitivity assays (hs-cTn) in the elderly is frequently found higher than the 99th percentile upper reference limit, making the diagnosis of acute coronary syndromes (ACS) difficult. This study aimed at: 1) identifying determinants of hs-cTnT levels in an unselected population of elderly subjects; and 2) assessing the prognosis value of increased hs-cTnT in elderly people free of ACS.
  
  
  METHODS
  Hs-cTnT was measured in 591 individuals aged over 65 years without suspicion of ACS. Comorbidities were assessed using the Cumulative Illness Rating Scale for Geriatrics (CIRS-G). C-reactive protein, α1-acid glycoprotein, albumin and creatinine were measured. Factors influencing hs-cTnT levels were assessed through linear regression and quantile regression was used to model percentiles of hs-cTnT. Risk of mortality was assessed through Cox regression.
  
  
  RESULTS
  Age, gender, cardiac CIRS-G, estimated glomerular filtration rate (p<0.001 for all), albumin (p<0.028) and α1-acid glycoprotein (p=0.002) were independent predictors of hs-cTnT. After exclusion of outliers, the median was 15 ng/L and 99th percentile was 64 ng/L. After controlling for comorbidities, the 99th percentile increased from 24 ng/L at age 65 to 53 ng/L at age 90 in females and from 33 ng/L to 75 ng/L in males. In multivariate analysis, hs-cTnT level was significantly related to mortality.
  
  
  CONCLUSIONS
  Hs-cTnT level is associated with inflammation and renal function in the elderly. Independently of comorbidities, hs-cTnT concentration increases exponentially with age after 65 years. Decision limits adapted to age and sex may be useful to patient management.
authors.forename: Nils
authors.initials: N
authors.lastname: Kuster
authors.forename: Karine
authors.initials: K
authors.lastname: Monnier
authors.forename: Gregory
authors.initials: G
authors.lastname: Baptista
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Dupuy
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Badiou
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Bargnoux
authors.forename: Claude
authors.initials: C
authors.lastname: Jeandel
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Cristol
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D001774:Blood Chemical Analysis / Q000592:standards*; D015897:Comorbidity; D005260:Female; D006801:Humans; D057230:Limit of Detection; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D012015:Reference Standards; D012306:Risk; D020107:Troponin T / Q000097:blood*
chemical_list: D020107:Troponin T