title: One-hour rule-in and rule-out of acute myocardial infarction using high-sensitivity cardiac troponin I.
abstract: OBJECTIVE
  We aimed to prospectively derive and validate a novel 1h-algorithm using high-sensitivity cardiac troponin I (hs-cTnI) for early rule-out and rule-in of acute myocardial infarction.
  
  
  METHODS
  We performed a prospective multicenter diagnostic study enrolling 1811 patients with suspected acute myocardial infarction. The final diagnosis was centrally adjudicated by 2 independent cardiologists using all available information, including coronary angiography, echocardiography, follow-up data, and serial measurements of hs-cTnT (but not hs-cTnI). The hs-cTnI 1h-algorithm, incorporating measurements performed at baseline and absolute changes within 1 hour, was derived in a randomly selected sample of 906 patients (derivation cohort), and then validated in the remaining 905 patients (validation cohort).
  
  
  RESULTS
  Acute myocardial infarction was the final diagnosis in 18% of patients. After applying the hs-cTnI 1h-algorithm developed in the derivation cohort to the validation cohort, 50.5% of patients could be classified as "rule-out," 19% as "rule-in," 30.5% as "observe." In the validation cohort, the negative predictive value for acute myocardial infarction in the "rule-out" zone was 99.6% (95% confidence interval, 98.4%-100%), and the positive predictive value for acute myocardial infarction in the "rule-in" zone was 73.9% (95% confidence interval, 66.7%-80.2%). Negative predictive value of the 1h-algorithm was higher compared with the classical dichotomous interpretation of hs-cTnI and to the standard of care combining hs-cTnI with the electrocardiogram (both P < .001). Positive predictive value also was higher compared with the standard of care (P < .001).
  
  
  CONCLUSIONS
  Using a simple algorithm incorporating baseline hs-cTnI values and the absolute change within the first hour allows safe rule-out as well as accurate rule-in of acute myocardial infarction in 70% of patients presenting with suspected acute myocardial infarction.
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland; Servicio de Urgencias y Pneumologia, CIBERES ISC III, Hospital del Mar-Institut Municipal d'Investigació Mèdica, Barcelona, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Rubini Gimenez
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Raphael
authors.initials: R
authors.lastname: Twerenbold
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Cedric
authors.initials: C
authors.lastname: Jaeger
authors.affiliation: Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, University Basel, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Schindler
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Puelacher
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Karin
authors.initials: K
authors.lastname: Wildi
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Tobias
authors.initials: T
authors.lastname: Reichlin
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Philip
authors.initials: P
authors.lastname: Haaf
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Salome
authors.initials: S
authors.lastname: Merk
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Ursina
authors.initials: U
authors.lastname: Honegger
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Max
authors.initials: M
authors.lastname: Wagener
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Sophie
authors.initials: S
authors.lastname: Druey
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Carmela
authors.initials: C
authors.lastname: Schumacher
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Lian
authors.initials: L
authors.lastname: Krivoshei
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Petra
authors.initials: P
authors.lastname: Hillinger
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Herrmann
authors.affiliation: Servicio de Urgencias y Pneumologia, CIBERES ISC III, Hospital del Mar-Institut Municipal d'Investigació Mèdica, Barcelona, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Campodarve
authors.affiliation: Laboratory Medicine, University Hospital Basel, Switzerland.
authors.forename: Katharina
authors.initials: K
authors.lastname: Rentsch
authors.affiliation: Department of Internal Medicine, University Hospital Basel, Switzerland.
authors.forename: Stefano
authors.initials: S
authors.lastname: Bassetti
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Osswald
authors.affiliation: Department of Cardiology and Cardiovascular Research Institute Basel, University Hospital Basel, Switzerland. Electronic address: Christian.Mueller@usb.ch.
authors.forename: Christian
authors.initials: C
authors.lastname: Mueller
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015415:Biomarkers / Q000097:blood; D002637:Chest Pain / Q000209:etiology; D004562:Electrocardiography; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013997:Time Factors; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I
keywords: Accurate rule-in; Acute myocardial infarction; Safe rule-out; hs-cTn