title: Clinical benefit of high-sensitivity cardiac troponin I in the detection of exercise-induced myocardial ischemia.
abstract: BACKGROUND
  A pilot study using a novel high-sensitivity cardiac troponin I (hs-cTnI) assay suggested that cTnI might be released into blood during exercise-induced myocardial ischemia. We investigated the potential clinical value of this signal.
  
  
  METHODS
  We included 819 patients with suspected exercise-induced myocardial ischemia referred for rest/bicycle myocardial perfusion single-photon emission computed tomography. The treating cardiologist used all available clinical information to quantify clinical judgment regarding the presence of myocardial ischemia using a visual analog scale twice: prior and after stress testing. High-sensitivity cTnI measurements were obtained before, immediately after peak stress, and 2 hours after stress testing in a blinded manner. Myocardial ischemia was adjudicated using perfusion single-photon emission computed tomography and coronary angiography findings.
  
  
  RESULTS
  Exercise-induced myocardial ischemia was detected in 278 (34%) patients. High-sensitivity cTnI levels were significantly higher at all time points in patients with myocardial ischemia as compared with those without (P < .001 for all). Combining clinical judgment prior exercise testing with baseline hs-cTnI levels increased diagnostic accuracy as quantified by the area under the receiver operating characteristics curve (AUC) from 0.672 to 0.757 (P < .001). Combining clinical judgment after exercise testing (AUC 0.704) with baseline or poststress hs-cTnI levels also increased the diagnostic accuracy (AUC 0.761-0.771, P < .001 for all). In contrast, exercise-induced changes in hs-cTnI during exercise did not seem useful, as they were small and similar in patients with or without myocardial ischemia.
  
  
  CONCLUSIONS
  High-sensitivity cTnI concentrations at rest and after exercise, but not its exercise-induced changes, provide substantial incremental value to clinical judgment including exercise electrocardiography regarding the presence of myocardial ischemia.
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Gino
authors.initials: G
authors.lastname: Lee
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Raphael
authors.initials: R
authors.lastname: Twerenbold
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Yunus
authors.initials: Y
authors.lastname: Tanglay
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Tobias
authors.initials: T
authors.lastname: Reichlin
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Ursina
authors.initials: U
authors.lastname: Honegger
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland; Department of Internal University Hospital, Basel, Switzerland.
authors.forename: Max
authors.initials: M
authors.lastname: Wagener
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Cedric
authors.initials: C
authors.lastname: Jaeger
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Maria
authors.initials: M
authors.lastname: Rubini Gimenez
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland; Department of Internal University Hospital, Basel, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hochgruber
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Puelacher
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Milos
authors.initials: M
authors.lastname: Radosavac
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Kreutzinger
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Fabio
authors.initials: F
authors.lastname: Stallone
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Petra
authors.initials: P
authors.lastname: Hillinger
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Lian
authors.initials: L
authors.lastname: Krivoshei
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Herrmann
authors.affiliation: Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Romy
authors.initials: R
authors.lastname: Mayr
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Freese
authors.affiliation: Division of Nuclear Medicine, University Hospital, Basel, Switzerland.
authors.forename: Damian
authors.initials: D
authors.lastname: Wild
authors.affiliation: Department of Laboratory Medicine, University Hospital, Basel, Switzerland.
authors.forename: Katharina M
authors.initials: KM
authors.lastname: Rentsch
authors.affiliation: Singulex, Alameda, CA.
authors.forename: John
authors.initials: J
authors.lastname: Todd
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Osswald
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zellweger
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland; Cardiovascular Research Institute Basel (CRIB), University Hospital, Basel, Switzerland. Electronic address: christian.mueller@usb.ch.
authors.forename: Christian
authors.initials: C
authors.lastname: Mueller
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D017023:Coronary Angiography; D004562:Electrocardiography; D015444:Exercise; D005080:Exercise Test / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood* / Q000175:diagnosis / Q000209:etiology; D009206:Myocardium / Q000378:metabolism*; D010865:Pilot Projects; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I