The Use in the United States of a Baseline High-Sensitivity Cardiac Troponin T Value Below the Level of Detection to Rule out Acute Myocardial Infarction

Document Type

Conference Proceeding

Publication Date


Publication Title

Acad Emerg Med


Background: The use of a single baseline high sensitivity cardiac troponin T (hs-cTnT) measurement < level of detection (LoD) to rule-out acute myocardial infarction (AMI) is recommended in the 2015 European Society of Cardiology guidelines. However, this suggestion is mostly based on trials including European populations and using a LoD for hs-cTnT of 5 ng/L. The purpose of this study was to determine if a single baseline hs-cTnT level < 6 ng/L (the FDA approved LoD) could rule-out AMI in a United States (US) Emergency Department (ED) population.

Methods: Patients presenting to the ED with any symptoms suspicious for ACS at a single US tertiary care urban center were enrolled. Baseline blood samples were obtained within 60 minutes of a triage ECG. AMI diagnosis was independently adjudicated by a cardiologist and emergency physician using the 3rd Universal Definition and serial troponin I (TnI) levels (Siemens TnI-Ultra) over 3 hours and all clinical data available 30 days post discharge.

Results: Of the 569 studied subjects 44 (7.7%) had AMI and all enrolled patients had a baseline blood sample drawn. There were 164 (28.8%) subjects that had a baseline hs-cTnT value < the LoD of 6 ng/L and all were without adjudicated AMI (negative predictive value 100% [95%CI 97.8-100.0], sensitivity 100% [95%CI 92.0-100.0]), irrespective of any ECG abnormalities. There were 30 hemodialysis patients enrolled and all had hs-cTn â%o¥ 6 ng/L at presentation. At 30 days there was 1 non-cardiac death, no cardiac deaths, 1 AMI (0.6%), and no revascularization procedures in those patients with a baseline hs-cTnT < 6 ng/ L. The past medical histories of subjects with a hs-cTnT < 6 ng/L included hypertension 98 (59.8%), diabetes mellitus 26 (15.9%), hypercholesterolemia 48 (29.3%), coronary artery disease 31 (18.9%), prior revascularization procedure 21 (12.8%), myocardial infarction 26 (15.9%), and congestive heart failure 11 (6.7%).

Conclusion: A single baseline hs-cTnT level < the US LoD of 6 ng/L can be used to rule-out AMI and identifies a low risk population which may be considered, after appropriate work up for non ACS etiologies as cause for presenting symptoms, for early discharge without further observation and/or cardiac testing. These findings are required to be validated prospectively in further multi-center US trials.



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