The Trouble with Troponin

Serial multiple biomarkers in the assessment of suspected acute coronary syndrome: multiple infarct markers in chest pain (MIMIC) study

“…Different troponin assays vary in their analytical performance 18. At the time of this study, the SMB cTnI had less low-range precision and a higher limit of detection than the contemporary laboratory troponin assays used at three of the study sites.…”

Rapid risk stratification in suspected acute coronary syndrome using serial multiple cardiac biomarkers: A pilot study

“…This issue is further complicated by the heterogeneity of commercially available cTnI assays, with differing analytical sensitivities and cut-offs, which makes comparisons difficult. 17 Over 90% of patients in the present study were ultimately deemed suitable for discharge from the ED. The median presentation time was between 2 and 3 h after onset of symptoms.…”

“…However, the combination of all three markers has been demonstrated to have higher sensitivity than troponin alone, 11 so the significance of this in practice is uncertain. This issue is further complicated by the heterogeneity of commercially available cTnI assays, with differing analytical sensitivities and cut‐offs, which makes comparisons difficult 17 …”

A non-ischaemic cause of elevated troponin

“…Elevations may be indicative of a variety of non-coronary disorders such as sepsis, renal failure, pulmonary embolism, hypotension, pericarditis and congestive heart failure 3. Also of note, false-positive results may be caused by antianimal ‘heterophile’ antibodies, antitroponin antibodies, fibrin clots,4 5 microparticles, analyser malfunction or rheumatoid factors 5. It is estimated that heterophilic antibodies interfere with assays in 2.0% of cases 6…”