title: Incidentally Raised Cardiac Troponin I Has a Worse Prognosis in Older Patients Compared to Those with Normal Cardiac Troponin I and Patients with Acute Coronary Syndrome: A Cohort Study.
abstract: Incidentally elevated cardiac troponin I (cTnI) levels are common in acutely unwell older patients. However, little is known about how this impacts on the prognosis of these patients.
  
  
  
  We aimed to investigate whether incidentally elevated cTnI levels (group 1) are associated with poorer outcome when compared to age- and sex-matched patients without an elevated cTnI level (group 2), and to patients diagnosed with acute coronary syndrome (group 3).
  
  
  
  This prospective, matched cohort study placed patients ≥75 years old who were admitted to a University teaching hospital into groups 1-3, based on the cTnI levels and underlying diagnosis. Outcomes were compared between the groups using mixed-effects regression models and adjusted for renal function and C-reactive protein. All-cause mortality at discharge, at 1 month and 3 months, alongside the length of hospital stay (LOS), were recorded.
  
  
  
  In total, 315 patients were included, with 105 patients in each of the 3 groups. The mean age was 84.8 ± 5.5 years, with 41.9% males. All patients were followed up for 3 months. The percent all-cause mortality at discharge and the LOS for groups 1, 2 and 3 were 12.4, 3.8 and 8.6% and 11.2, 8.5 and 7.7 days, respectively. Group 1 had significantly increased mortality at 3 months [odds ratio (OR) 2.80, 95% confidence interval (CI) 1.12-6.96; p = 0.040] and LOS (OR 1.39, 95% CI 1.08-1.79; p = 0.008) compared to group 2 and did not differ significantly when compared to 3-month mortality (OR 2.39, 95% CI 0.91-6.29; p = 0.079) or LOS (OR 1.26, 95% CI 0.96-1.66; p = 0.097) in group 3.
  
  
  
  There is a significant association between an incidental rise in cTnI level with mortality and LOS in older patients. Further research is required to evaluate whether a more systematic management of these patients would improve the prognosis.
authors.affiliation: Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
authors.forename: Gurdeep Singh
authors.initials: GS
authors.lastname: Mannu
authors.forename: Katie
authors.initials: K
authors.lastname: Honney
authors.forename: Robert
authors.initials: R
authors.lastname: Spooner
authors.forename: Allan B
authors.initials: AB
authors.lastname: Clark
authors.forename: Joao H
authors.initials: JH
authors.lastname: Bettencourt-Silva
authors.forename: M Justin S
authors.initials: MJ
authors.lastname: Zaman
authors.forename: Yoon K
authors.initials: YK
authors.lastname: Loke
authors.forename: Phyo K
authors.initials: PK
authors.lastname: Myint
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood / Q000401:mortality*; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D033162:Incidental Findings; D007902:Length of Stay; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I; D002097:C-Reactive Protein