High-Sensitivity Cardiac Troponin T in Clinical Practice | Journal Scan

Study Questions:

What are the implications of introducing high-sensitivity cardiac troponin T (hs-cTnT) into clinical practice?

Methods:

The investigators analyzed data from 48,594 patients admitted because of symptoms suggesting an acute coronary syndrome and who were entered into a large national registry. Patients were divided into: Group 1—those with hs-cTnT <6 ng/L; Group 2—hs-cTnT 6-13 ng/L; Group 3—hs-cTnT 14-49 ng/L (i.e., a group in which most patients would have had a negative cTnT with older assays); and Group 4—hs-cTnT 250 ng/L.

Results:

There were 5,790 (11.9%), 6,491(13.4%), 10,476 (21.6%), and 25,837 (53.2%) patients in groups 1-4, respectively. From groups 1-4, the proportion with myocardial infarction (MI) was 2.2%, 2.6%, 18.2%, and 81.2%, respectively. There was a stepwise increase in the proportion of patients with significant coronary stenoses, left ventricular systolic dysfunction, and death during follow-up. When dividing patients into 20 groups according to hs-cTnT level, the adjusted mortality started to increase at an hs-cTnT level of 14 ng/L.

Conclusions:

The authors concluded that introducing hs-cTnT into clinical practice has led to the recognition of a large proportion of patients with minor cTn elevations, the majority of whom do not have MI.

Perspective:

This study reports that in a nonselected high-risk population, the introduction of hs-cTnT led to the identification of a large proportion of patients with minor cTn elevations, a group in which most patients would have had a negative cTnT if the old cTnT assay had been used. After adjusting for differences in baseline characteristics, long-term mortality starts to increase at the level of the 99th percentile in healthy controls with a stepwise increase in mortality with increasing levels of hs-cTnT, regardless of the underlying cause of cTn elevation. Overall, the study suggests that hs-cTnT may lead to better risk assessment, but needs to be validated in larger prospective studies.

Keywords: Acute Coronary Syndrome, Coronary Stenosis, Mortality, Myocardial Infarction, Registries, Risk Assessment, Troponin, Troponin T


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