title: Comparison of new point-of-care troponin assay with high sensitivity troponin in diagnosing myocardial infarction.
abstract: OBJECTIVE
  The aim of this study is to compare a new improved point of care cardiac troponin assay (new POC-cTnI) with 1. its predecessor (old POC-cTnI) and 2. a high sensitivity assay (hs-cTnI) for the diagnosis of acute myocardial infarction (AMI) and for major adverse cardiac events (MACE) by 30 days.
  
  
  METHODS
  This is a single centre observational study, set in Christchurch Hospital, New Zealand. Patients presenting to the emergency department with non-traumatic chest pain underwent blood sampling at 0 h and 2h post presentation for analysis with the 3 cTnI assays for the outcome of AMI and for analysis using an accelerated diagnostic protocol (ADP-normal 2h troponins, normal electrocardiograms and Thrombolysis In Myocardial Infarction (TIMI) score of 0 or ≤ 1) for 30 day MACE.
  
  
  RESULTS
  Of 962 patients, 220 (22.9%) had AMI. Old POC-cTnI was least sensitive at 70.0% (65.4-73.9%) by 2h (p<0.001). New POC-cTnI, sensitivity 93.6% (89.9-96.2%) had similar sensitivity to hs-cTnI, sensitivity 95.0% (91.5-97.3%) (p = 0.508). There were 231 (24.0%) patients with 30 day MACE. When used as part of the ADP, all assays had 100% (98.0-100%) sensitivity using TIMI = 0. Sensitivities of new POC-cTnI ADP, 98.3% (95.4-99.4%), old POC-cTnI, 96.5% (93.2-98.4%) and hs-cTnI, 98.7% (96.0-99.7%) were similar (p = 0.063-0.375) using TIMI ≤ 1.
  
  
  CONCLUSIONS
  A new POC-cTnI has improved sensitivity for AMI and MACE compared with its predecessor and comparable sensitivity to a high sensitivity assay. Now that sensitivities of the POC assay are improved, the new assay may be a useful alternative to central laboratory assays when rapid turn-around times are not possible.
authors.affiliation: Department of Cardiology, Christchurch Hospital, Riccarton Avenue, Christchurch, New Zealand. Electronic address: sally.aldous@cdhb.health.nz.
authors.forename: Sally
authors.initials: S
authors.lastname: Aldous
authors.affiliation: Christchurch Hospital, Christchurch, New Zealand; University of Otago, Christchurch, New Zealand; National University Heart Centre, Singapore.
authors.forename: A
authors.initials: A
authors.lastname: Mark Richards
authors.affiliation: Canterbury Health Laboratories, Christchurch, New Zealand.
authors.forename: Peter M
authors.initials: PM
authors.lastname: George
authors.affiliation: Royal Brisbane and Women's Hospital, Brisbane, Australia.
authors.forename: Louise
authors.initials: L
authors.lastname: Cullen
authors.affiliation: Royal Brisbane and Women's Hospital, Brisbane, Australia.
authors.forename: William A
authors.initials: WA
authors.lastname: Parsonage
authors.affiliation: University of Technology, Brisbane, Australia.
authors.forename: Dylan
authors.initials: D
authors.lastname: Flaws
authors.affiliation: Canterbury Health Laboratories, Christchurch, New Zealand.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Florkowski
authors.affiliation: Christchurch Hospital, Christchurch, New Zealand; University of Otago, Christchurch, New Zealand.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Troughton
authors.affiliation: Royal Brisbane and Women's Hospital, Brisbane, Australia.
authors.forename: Jack W
authors.initials: JW
authors.lastname: O'Sullivan
authors.affiliation: Monash University, Melbourne, Australia.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Reid
authors.affiliation: Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Laura
authors.initials: L
authors.lastname: Bannister
authors.affiliation: Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Martin
authors.initials: M
authors.lastname: Than
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis*; D019095:Point-of-Care Systems; D011379:Prognosis; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014336:Troponin / Q000097:blood*
chemical_list: D015415:Biomarkers; D014336:Troponin
keywords: Accelerated diagnostic protocol; Acute myocardial infarction; High sensitivity troponin; Major adverse cardiac events; Point of care troponin