Detection of acute changes in circulating troponin in the setting of transient stress test-induced myocardial ischaemia using an ultrasensitive assay: results from TIMI 35

Eur Heart J. 2009 Jan;30(2):162-9. doi: 10.1093/eurheartj/ehn504. Epub 2008 Nov 8.


Aims: To determine whether an ultrasensitive assay can permit quantification of changes in circulating cardiac troponin (Tn) in the setting of stress test-induced myocardial ischaemia.

Methods and results: Blood samples were obtained before, immediately after, and 2 and 4 h after stress testing with nuclear perfusion imaging in 120 patients. Troponin was measured using commercial assays as well as with a novel, ultrasensitive cardiac TnI assay with a limit of detection of 0.2 pg/mL. Using the ultrasensitive assay, TnI was detectable in all patients before stress testing (median 4.4 pg/mL, interquartile range 3.1-8.6 pg/mL). By 4 h, troponin levels were unchanged in patients without ischaemia, whereas circulating levels had increased by a median of 1.4 pg/mL (24% increase) in patients with mild ischaemia (P = 0.002) and by 2.1 pg/mL (40% increase) in patients with moderate-to-severe ischaemia (P = 0.0006). In contrast, changes in troponin levels across patients in different ischaemic categories were indistinguishable using commercial troponin assays. When added to clinical factors, a >1.3 pg/mL increase in TnI using the ultrasensitive assay was an independent predictor of ischaemia (odds ratio 3.54, P = 0.007).

Conclusion: Transient stress test-induced myocardial ischaemia is associated with a quantifiable increase in circulating troponin that is detectable with a novel, ultrasensitive TnI assay.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Biomarkers / blood
  • Epidemiologic Methods
  • Exercise Test / adverse effects
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myocardial Ischemia / blood
  • Myocardial Ischemia / diagnosis*
  • Myocardial Ischemia / etiology
  • Troponin I / blood*


  • Biomarkers
  • Troponin I