title: Validation of high-sensitivity troponin I in a 2-hour diagnostic strategy to assess 30-day outcomes in emergency department patients with possible acute coronary syndrome.
abstract: OBJECTIVE
  The study objective was to validate a new high-sensitivity troponin I (hs-TnI) assay in a clinical protocol for assessing patients who present to the emergency department with chest pain.
  
  
  BACKGROUND
  Protocols using sensitive troponin assays can accelerate the rule out of acute myocardial infarction in patients with low-risk (suspected) acute coronary syndrome (ACS).
  
  
  METHODS
  This study evaluated 2 prospective cohorts of patients in the emergency department with ACS in an accelerated diagnostic pathway integrating 0- and 2-h hs-TnI results, Thrombolysis In Myocardial Infarction (TIMI) risk scores, and electrocardiography. Strategies to identify low-risk patients incorporated TIMI risk scores= 0 or ≤ 1. The primary endpoint was a major adverse cardiac event (MACE) within 30 days.
  
  
  RESULTS
  In the primary cohort, 1,635 patients were recruited and had 30-day follow-up. A total of 247 patients (15.1%) had a MACE. The finding of no ischemic electrocardiogram and hs-TnI ≤ 26.2 ng/l with the TIMI = 0 and TIMI ≤ 1 pathways, respectively, classified 19.6% (n = 320) and 41.5% (n = 678) of these patients as low risk; 0% (n = 0) and 0.8% (n = 2) had a MACE, respectively. In the secondary cohort, 909 patients were recruited. A total of 156 patients (17.2%) had a MACE. The TIMI = 0 and TIMI ≤ 1 pathways classified 25.3% (n = 230) and 38.6% (n = 351), respectively, of these patients as low risk; 0% (n = 0) and 0.8% (n = 1) had a MACE, respectively. Sensitivity, specificity, and negative predictive value for TIMI = 0 in the primary cohort were 100% (95% confidence interval [CI]: 98.5% to 100%), 23.1% (95% CI: 20.9% to 25.3%), and 100% (95% CI: 98.8% to 100%), respectively. Sensitivity, specificity, and negative predictive value for TIMI ≤ 1 in the primary cohort were 99.2 (95% CI: 97.1 to 99.8), 48.7 (95% CI: 46.1 to 51.3), and 99.7 (95% CI: 98.9 to 99.9), respectively. Sensitivity, specificity, and negative value for TIMI ≤ 1 in the secondary cohort were 99.4% (95% CI: 96.5 to 100), 46.5% (95% CI: 42.9 to 50.1), and 99.7% (95% CI: 98.4 to 100), respectively.
  
  
  CONCLUSIONS
  An early-discharge strategy using an hs-TnI assay and TIMI score ≤ 1 had similar safety as previously reported, with the potential to decrease the observation periods and admissions for approximately 40% of patients with suspected ACS. (Advantageous Predictors of Acute Coronary Syndromes Evaluation [APACE] Study, NCT00470587; A 2 hr Accelerated Diagnostic Protocol to Assess patients with chest Pain symptoms using contemporary Troponins as the only biomarker [ADAPT]: a prospective observational validation study, ACTRN12611001069943).
authors.affiliation: Royal Brisbane and Women's Hospital, Herston, Australia; Queensland University of Technology, Brisbane, Australia. Electronic address: louise_cullen@health.qld.gov.au.
authors.forename: Louise
authors.initials: L
authors.lastname: Cullen
authors.affiliation: University Hospital Basel, Basel, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Mueller
authors.affiliation: Royal Brisbane and Women's Hospital, Herston, Australia; University of Queensland, Brisbane, Australia.
authors.forename: William A
authors.initials: WA
authors.lastname: Parsonage
authors.affiliation: University Hospital Basel, Basel, Switzerland.
authors.forename: Karin
authors.initials: K
authors.lastname: Wildi
authors.affiliation: Royal Brisbane and Women's Hospital, Herston, Australia; Queensland University of Technology, Brisbane, Australia; University of Queensland, Brisbane, Australia.
authors.forename: Jaimi H
authors.initials: JH
authors.lastname: Greenslade
authors.affiliation: University Hospital Basel, Basel, Switzerland.
authors.forename: Raphael
authors.initials: R
authors.lastname: Twerenbold
authors.affiliation: Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Sally
authors.initials: S
authors.lastname: Aldous
authors.affiliation: University Hospital Basel, Basel, Switzerland.
authors.forename: Bernadette
authors.initials: B
authors.lastname: Meller
authors.affiliation: Royal Brisbane and Women's Hospital, Herston, Australia.
authors.forename: Jillian R
authors.initials: JR
authors.lastname: Tate
authors.affiliation: University Hospital Basel, Basel, Switzerland; Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Tobias
authors.initials: T
authors.lastname: Reichlin
authors.affiliation: Royal Brisbane and Women's Hospital, Herston, Australia.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hammett
authors.affiliation: University Hospital Basel, Basel, Switzerland.
authors.forename: Christa
authors.initials: C
authors.lastname: Zellweger
authors.affiliation: Royal Brisbane and Women's Hospital, Herston, Australia.
authors.forename: Jacobus P J
authors.initials: JPJ
authors.lastname: Ungerer
authors.affiliation: University Hospital Basel, Basel, Switzerland.
authors.forename: Maria
authors.initials: M
authors.lastname: Rubini Gimenez
authors.affiliation: University of Otago, Christchurch, New Zealand.
authors.forename: Richard
authors.initials: R
authors.lastname: Troughton
authors.affiliation: University Hospital Basel, Basel, Switzerland.
authors.forename: Karsten
authors.initials: K
authors.lastname: Murray
authors.affiliation: Royal Brisbane and Women's Hospital, Herston, Australia; University of Queensland, Brisbane, Australia.
authors.forename: Anthony F T
authors.initials: AFT
authors.lastname: Brown
authors.affiliation: University Hospital Basel, Basel, Switzerland.
authors.forename: Mira
authors.initials: M
authors.lastname: Mueller
authors.affiliation: Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Peter
authors.initials: P
authors.lastname: George
authors.affiliation: University Hospital Basel, Basel, Switzerland.
authors.forename: Tamina
authors.initials: T
authors.lastname: Mosimann
authors.affiliation: University of Queensland, Brisbane, Australia.
authors.forename: Dylan F
authors.initials: DF
authors.lastname: Flaws
authors.affiliation: University Hospital Basel, Basel, Switzerland.
authors.forename: Miriam
authors.initials: M
authors.lastname: Reiter
authors.affiliation: Royal Brisbane and Women's Hospital, Herston, Australia.
authors.forename: Arvin
authors.initials: A
authors.lastname: Lamanna
authors.affiliation: University Hospital Basel, Basel, Switzerland.
authors.forename: Philip
authors.initials: P
authors.lastname: Haaf
authors.affiliation: University of Otago, Christchurch, New Zealand.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Pemberton
authors.affiliation: University of Otago, Christchurch, New Zealand.
authors.forename: A Mark
authors.initials: AM
authors.lastname: Richards
authors.affiliation: Royal Brisbane and Women's Hospital, Herston, Australia; University of Queensland, Brisbane, Australia.
authors.forename: Kevin
authors.initials: K
authors.lastname: Chu
authors.affiliation: Monash University, Melbourne, VIC, Australia.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Reid
authors.affiliation: Baylor College of Medicine, Houston, Texas.
authors.forename: William Frank
authors.initials: WF
authors.lastname: Peacock
authors.affiliation: Mayo Clinic, Rochester, Minnesota.
authors.forename: Allan S
authors.initials: AS
authors.lastname: Jaffe
authors.affiliation: Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Christopher
authors.initials: C
authors.lastname: Florkowski
authors.affiliation: Canterbury District Health Board, Christchurch, New Zealand.
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Deely
authors.affiliation: Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Martin
authors.initials: M
authors.lastname: Than
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D002637:Chest Pain / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D003325:Coronary Care Units / Q000706:statistics & numerical data*; D042241:Early Diagnosis; D005500:Follow-Up Studies; D006801:Humans; D017410:Practice Guidelines as Topic; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood*
chemical_list: D019210:Troponin I
keywords: ACS; ADAPT; ADP; AMI; APACE; CI; ECG; MACE; TIMI; Thrombolysis In Myocardial Infarction; accelerated diagnostic protocol; acute coronary syndrome(s); acute myocardial infarction; chest pain; confidence interval; electrocardiography; high-sensitivity troponin I; hs-TnI; major adverse cardiac event(s)