Clinical Use of High-sensitivity Cardiac Troponin in Patients With Suspected Myocardial Infarction

Raphael Twerenbold, MD; Jasper Boeddinghaus, MD; Thomas Nestelberger, MD; Karin Wildi, MD; Maria Rubini Gimenez, MD; Patrick Badertscher, MD; Christian Mueller, MD

Disclosures

J Am Coll Cardiol. 2017;70(8):996-1012. 

In This Article

Should We Measure hs-cTn in Patients With Low Pre-test Probability?

There is concern that hs-cTn may have low diagnostic accuracy in patients with low pre-test probability for ACS. Concern of misinterpretation of these hs-cTn elevations as MI and patient harm associated with potential unnecessary therapies such as anticoagulation and coronary angiography has led some experts to recommend withholding cTn testing in patients with low pre-test probability for ACS.[106,107] By contrast, practice guidelines highlight that MI frequently presents with atypical symptoms (e.g., in women and elderly patients), and mandate high scrutiny for MI, which means ECG and cTn testing also in patients with atypical symptoms.[27,41] These divergent recommendations result in uncertainty in clinical practice regarding cTn testing in patients with low pre-test probability for ACS.

Previous research focused predominantly on the evaluation of elevated cTn levels in unselected patients.[108–111] Patients with high initial cTn levels had a much higher incidence of Type I MI and that sensitivity and specificity of s-cTn increased with serial testing.[108] Thus, the implementation of the kinetics of the marker could provide some reassurance regarding the widespread concern of too many false-positive results in patients with low likelihood of ACS. A recent retrospective analysis reported low specificity for hs-cTnT to diagnose MI when grouping ED patients with suspected MI with patients with acute heart failure and patients with documented pulmonary embolism.[109] Hence, it is very important to highlight that diagnostic testing with hs-cTn should be applied to the correct population, at the optimal time and in the appropriate clinical context. In patients presenting with acute chest discomfort at least possibly suggestive of MI, the standard of care using clinical assessment and the 12-lead ECG in conjunction with hs-cTn should be applied also in a rather low pre-test probability setting. This recommendation is specific for patients presenting with any kind of chest discomfort to the ED and do not apply to patients without any chest pain, for example, patients with a stroke[112] or critically ill patients in the intensive care unit.[113] Although useful in patients presenting with acute chest pain, hs-cTn should not be used as a general screening test for MI in an unselected ED population.

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