title: How safe is the outpatient management of patients with acute chest pain and mildly increased cardiac troponin concentrations?
abstract: BACKGROUND
  The appropriate management of patients discharged from the emergency department (ED) with increased high-sensitivity cardiac troponin T (hs-cTnT) but normal or borderline-high conventional cardiac troponin concentrations is unknown.
  
  
  METHODS
  We investigated 643 consecutive ED patients with acute chest pain who had been discharged for outpatient management after acute myocardial infarction (AMI) had been ruled out by serial measurements of conventional cardiac troponin. hs-cTnT was measured blindly, and we calculated the rates of all-cause mortality (primary endpoint) and subsequent AMI (secondary endpoint) at 30, 90, and 360 days.
  
  
  RESULTS
  hs-cTnT concentrations were increased (>14 ng/L) in 114 patients (18%) but <30 ng/L in 95% of these patients. Of those 114 patients, 96 (84%) had an adjudicated noncoronary cause of chest pain. Thirty-day mortality (95% CI) was 0.9% (0.1%-6.1%), 90-day mortality was 2.7% (0.9%-8.1%), and 360-day mortality was 5.2% (2.2%-11.9%) in patients with increased hs-cTnT; respective rates (95% CI) of AMI were 0.0%, 1.9% (0.5%-7.2%), and 7.6% (3.7%-15.3%). Increased hs-cTnT was associated with increased mortality and AMI at 90 days (P = 0.006 and P = 0.081, respectively) and 360 days (P = 0.001 for both).
  
  
  CONCLUSIONS
  hs-cTnT is a strong prognosticator of intermediate and long-term mortality and AMI in low-risk patients discharged from the ED after AMI has been ruled out. The relatively low rate of 30-day events may suggest that patients without acute coronary syndrome and small increases in cardiac troponin are in need of further investigations and treatments, but not necessarily immediate hospitalization.
authors.affiliation: Department of Internal Medicine, University Hospital, Basel, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Meune
authors.forename: Tobias
authors.initials: T
authors.lastname: Reichlin
authors.forename: Affan
authors.initials: A
authors.lastname: Irfan
authors.forename: Nora
authors.initials: N
authors.lastname: Schaub
authors.forename: Raphael
authors.initials: R
authors.lastname: Twerenbold
authors.forename: Julia
authors.initials: J
authors.lastname: Meissner
authors.forename: Miriam
authors.initials: M
authors.lastname: Reiter
authors.forename: Adrian
authors.initials: A
authors.lastname: Lüthi
authors.forename: Philip
authors.initials: P
authors.lastname: Haaf
authors.forename: Cathrin
authors.initials: C
authors.lastname: Balmelli
authors.forename: Beatrice
authors.initials: B
authors.lastname: Drexler
authors.forename: Katrin
authors.initials: K
authors.lastname: Winkler
authors.forename: Willibald
authors.initials: W
authors.lastname: Hochholzer
authors.forename: Stefan
authors.initials: S
authors.lastname: Osswald
authors.forename: Christian
authors.initials: C
authors.lastname: Mueller
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care; D002637:Chest Pain / Q000175:diagnosis* / Q000401:mortality; D004632:Emergency Medical Services; D023381:Endpoint Determination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D009203:Myocardial Infarction / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D020107:Troponin T / Q000097:blood*
chemical_list: D020107:Troponin T