Department of Emergency Medicine
Mount Sinai Hospital
One Gustave Levy Place, Box 1149
New York, NY 10029-6574
Memorandum
Date: May 29, 2019
To: ED and RETU PAs, Residents, and Attendings
From: Jolion McGreevy, MD, ED Medical Director; Jonathan Yeo, MD, RETU Medical Director
Re: New Troponin Reference Range New Troponin Reference Range As of April, 22nd, 2019, the definition of a positive troponin I level has been changed from > 0.5 ng/mL to > 0.03 ng/mL. This modification changes the level for the presence of myocardial injury to the 99th percentile of upper reference limit of the assay. The criteria for MI includes detection of a rise and/or fall of troponin with at least one value above the 99th percentile and at least one of the following:
Symptoms of acute myocardial ischemia
New ischemic ECG changes
Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality
Interpreting a Positive Troponin The Departments of Cardiology, Medicine, and Emergency Medicine have developed the following algorithm to interpret positive troponin values: 1. For any positive troponin value (i.e., > 0.03) a second troponin should be checked at 3 hours. 2. If the index troponin is in the "low positive range" (0.04 – 0.09), an absolute change in the second troponin of 0.02 or more should be considered a clinically significant change. 3. If the index troponin is >= 0.1 (> 3x the upper limit of normal) the percent difference between the index and second troponin may be used to determine whether a change is clinically meaningful. Ischemia is suggested if the 2nd troponin has increased by more than 20% and there are symptoms and/or ECG changes suggestive of ischemia.
Can a Patient with a Low-positive Troponin Go to RETU?
Yes, if the troponin is low-positive (< 0.1) and the patient does not have a concerning story, the patient may go to RETU and have the second troponin drawn there in 3 hours.
Negative troponin (<= 0.03) can go to RETU.
Troponin 0.04 to 0.09 (3x upper limit of normal) without a concerning story can go to RETU after first troponin. RETU will send second troponin.
Troponin 0.04 to 0.09 with a concerning story needs second troponin in ED prior to RETU. Or consider other disposition.
Trop >= 0.1 cannot go to RETU.