Is 6 Hours the Magic Number for High Sensitivity Troponin?
December 27, 2022
Written by Gabby Leonard
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No patients with a high sensitivity troponin (hsTn) < 99th percentile of upper reference limit (URL) – drawn 6 hours after symptom onset – had death, arrest, STEMI, or life-threatening arrhythmia; 3 had NSTEMI.
Why does this matter?
hsTn is a diagnostic tool used to rapidly assess for myocardial infarction, which decreases length-of-stay and unnecessary admission in select patients presenting with chest pain. Some patients can be rapidly discharged with 0/1-hour or 0/3-hour protocols. However, many patients have hsTn levels above the lower limit of detection, which places them in an intermediate risk group, and management of these patients is less clear. What if such patients had a hsTn <99th percentile URL at 6 hours from symptom onset?
Magic…six ball?
This was a retrospective study of patients who did not meet rapid rule out criteria and were admitted for chest pain. They sought to determine if a hsTn cutoff value <99th percentile URL was sufficient to rule out clinically relevant adverse cardiac events when hsTn was drawn 6 hours after symptom onset.
0% of 429 patients admitted solely for acute chest pain with 6h hsTn < 99th percentile URL experienced adverse cardiac events during hospitalization; 3 developed NSTEMI. 29 total patients admitted solely for chest pain developed NSTEMI during admission, and 26/29 of these patients had a hsTn > 99th percentile URL within 6h of symptom onset. None of the three with NSTEMI and delayed elevation of hsTn experienced adverse cardiac events during hospitalization.
Patients presenting with chest pain who do not meet rapid rule out criteria but have a hsTn <99th percentile URL 6h after symptom onset may be considered for discharge, with close cardiology follow-up, to avoid costly hospitalizations and unwarranted testing.
Source
High sensitivity troponin – Six hours is the magic number. Am J Emerg Med. 2022 Nov;61:52-55. doi: 10.1016/j.ajem.2022.08.037. Epub 2022 Aug 19.
Reviewed by Clay Smith
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