- Written by Ethan Abbott
Sorry for the late post!!
For this week’s question:
High sensitivity troponin assays have been recently approved by the FDA for use in the United States. What is a high sensitivity troponin assay and how does it differ from a conventional troponin assay? What are the advantages and disadvantages of this assay?
Answer: A high sensitivity troponin assay essentially detects the same proteins as conventionally available assays but is able to detect these proteins at much lower concentrations. In statistical terms this means, “To be classified as high-sensitivity assays, concentrations below the 99th percentile should be detectable above the assay’s limit of detection for >50% of healthy individuals in the population of interest.”
The assays confer the advantage of earlier and faster recognition of patients with acute MI. They essentially shorten the time it would take to “rule out” a patient in the emergency department down to 1-3 hours. The high sensitivity troponins are also able to detect AMI with symptom onset within three hours of presentation. However this increased sensitivity can also lead to a high rate of false positives. Per the attached article, “Research with high-sensitivity assays shows both a nominal level of high-sensitivity troponin at baseline in apparently healthy individuals and the presence of biological variability over time.” Clearly use of these assays will require further study and investigation to determine how they can be most effectively utilized. Take a look at the attached article for a comprehensive review of these issues and pitfalls and how this assay could change our practice and management of patients presenting with suspected AMI.
Reference: High-Sensitivity Troponin Assays: Evidence, Indications, and Reasonable Use Matthew W. Sherwood, MD; L. Kristin Newby, MD, MHS