Clinical research studyUsing High-sensitivity Troponin T: The Importance of the Proper Gold Standard
Section snippets
Patients and Samples
TUSCA was a prospective multicenter trial involving 5 emergency departments. It enrolled 358 patients with acute coronary syndromes. To minimize selection bias, single physicians enrolled patients after discussions concerning inclusion criteria. Consecutive patients were included if they were aged >18 years, gave a history of ≥5 minutes of symptoms, and signed informed consent. Exclusion criteria included ST-segment elevation, new left bundle branch block, pre-admission thrombolytic therapy,
Patients
Of the 358 study patients, non-ST-segment elevation myocardial infarction was diagnosed by central adjudication in 79 (22.1%) (Table 1). Unstable angina and nonacute coronary syndromes were diagnosed in 105 patients (29.3%) and 174 patients (48.6%), respectively. Time from onset of symptoms to presentation was available in 88% of patients; 42 patients with myocardial infarction presented within 3 hours of symptoms. A mean of 3.7 samples per patient was obtained; patients lacking all 4 samples
Discussion
These data elucidate important issues concerning the use of hscTnT to diagnose myocardial infarction. Previous reports often relied on cTnT as the gold standard. Our data now document how markedly this alters analyses. The less sensitive gold standard identifies larger infarctions23 and thus exaggerates the benefits of the hscTnT assay. When cTnTCV is used as the gold standard,17,3 it further exaggerates differences, and 14% of acute myocardial infarctions detected using cTnT99 are missed. A
Conclusions
These data provide information about how to use the hscTnT assay to diagnose myocardial infarction. Performance is optimized by using the assay as its own gold standard. Doing so changes the optimal criteria for ruling, the rapidity of diagnosis, the magnitude of the change in values needed for diagnosis, and the specificity of diagnosis while diagnosing additional patients with myocardial infarction.
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Cited by (0)
Funding: Roche Diagnostics Spain provided reagents for and supported the logistics but was not involved in the analyses.
Conflict of Interest: MS has received honoraria as speaker from Roche Diagnostics. ASJ acknowledges that he does consult or has consulted for most of the major diagnostic companies. JO-L declares that he has received significant financial support for research and honoraria for consultation from Abbott Diagnostics, Alere, and Roche Diagnostics. None of the other authors have any conflicts of interest associated with the work presented in this manuscript.
Authorship: All authors had access to the data and played a role in writing this manuscript.
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ASJ and JO-L co-directed the work.