Document Type

Conference Proceeding

Publication Date


Publication Title

J Am Coll Cardiol


Background: We compared the safety of our standard protocol to a new 0/1-hour high-sensitivity cardiac troponin I (hs-cTnI) protocol for exclusion of myocardial infarction (MI).

Methods: A stepped-wedge randomized trial of patients evaluated for possible MI in 9 Emergency Departments (ED) (urban and suburban) in the Henry Ford Health System (Detroit, MI) were studied from 7/2020-3/2021. Trial arms included the new 0/1-hour protocol and standard care. A hs-cTnI assay from Beckman Coulter was used (99th percentile 18 ng/L). Patients were excluded if any hs-cTnI was >18 ng/L within 3 hours or they were admitted to the hospital. In the 0/1-hour algorithm, MI was excluded if hs-cTnI <4 ng/L at time 0, or = 4 ng/L at time 0 with 1 hour <8 ng/L. The algorithm advised ED discharge if patients ruled-out by the 0/1-hour protocol. Otherwise, the protocol included another hs-cTnI at 3 hours. In the standard care arm, hs-cTnI was measured at 0 and 3 hours with values ≤18 ng/L used to exclude AMI and guide ED discharge decisions. The primary outcome was adjudicated death or MI at 30 days. The analysis included a mixed effect model adjusting for ED site, time, sex, age, and race.

Results: There were 22,345 patients in the trial. At 30 days there were 24 deaths and 26 MIs. There was no significant difference between the death/MI rate between the standard of care group and the accelerated protocol (Table).

Conclusion: Implementation of the 0/1-hour algorithm to evaluate for MI in the ED was safe when compared to standard care.





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