At 10:00 am tomorrow, Tuesday, March 9th, the University of Iowa Hospitals and Clinics will change to a high-sensitivity cardiac troponin T assay (LAB9092).  This new troponin test will be offered at the Core Laboratory and at Iowa River Landing.  Future orders placed before 10:00 am on March 9th will be completed using the current troponin test.  Order sets with the current troponin test will be immediately replaced with the high-sensitivity test.  Individual preference lists will also be updated by the end of the day on March 9th.  The current troponin test will be discontinued.

A protocol for the use of high-sensitivity cardiac troponin T in the evaluation of patients with acute chest pain was developed via collaboration between Emergency Medicine, Cardiology, Hospitalist, and Pathology teams.

Details on the new method are as follows:

• High-sensitivity cardiac troponin assays are 5 – 10 fold more analytically sensitive than current troponin assays and are recommended for routine clinical use (Fourth Universal Definition of Myocardial Infarction, 2018).


• High-sensitivity cardiac troponin T (hs-cTnT) results will be reported using different units (ng/L) compared to the current troponin assay (ng/mL).  For example, 0.10 ng/mL = 100 ng/L.


• Elevations in hs-cTnT above the upper 99th percentile limit (14 ng/L for adult females, 22 ng/L for adult males) are sensitive for myocardial injury.


• Myocardial injury may be due to acute myocardial ischemia or other causes (e.g., myocarditis, heart failure, sepsis, chronic kidney disease, pulmonary embolism, strenuous exercise).  Serial hs-cTnT monitoring and clinical correlation are required to diagnose acute myocardial infarction.


• Results available within 1 hour of specimen receipt in the laboratory


• Specimen type unchanged – PST tube required


• Add-ons allowed for 36 hours after specimen collection


• Hemolysis should be avoided, as proteases released by RBCs degrade troponin T.  Testing will be cancelled when hemolysis is severe enough to induce significant error.

Questions should be directed to Anna Merrill, PhD (678-8400, pager 7046, anna-merrill@uiowa.edu) or Matthew Krasowski, MD, PhD (pager 1171, matthew-krasowski@uiowa.edu).