A Negative High-Sensitivity Troponin and Reassuring EKG Can Rule out Acute MI

by Joseph Esherick, M.D., FAAFP, FHM

One of the more common presenting complaints to an ED is the adult presenting with chest pain.  In addition, one of the most common reasons for admission to a hospitalist service is the "Chest pain rule out MI" admitting diagnosis.  Part of this is the difficulty determining which adult presenting with chest pain has an acute coronary syndrome versus some noncardiac cause of chest pain.

Several studies have demonstrated the potential utility of high-sensitivity cardiac troponin T (hs-cTnT) assays combined with reassuring electrocardiograms (EKGs) in the rapid rule-out of acute myocardial infarction (AMI) in adults presenting to the emergency department with chest pain. This meta-analysis of 11 studies confirms the efficacy of a single negative hs-cTnT measured at least 3 hours after chest pain onset plus a nonischemic ECG for ruling out AMI in adults presenting to the ED.

This meta-analysis evaluated a total of 9241 patients and 2825 (30.6%) were deemed to be low risk (hs-cTnT<0.005 µg/L and nonischemic ECG). Only 14 low-risk patients (0.5%) had AMI during the index hospital admission, and blood was drawn for the single hs-cTnT test less than 3 hours after symptom onset in half of these patients.

A negative hs-cTnT in association with a reassuring EKG had a negative predictive value of 99.3% for ruling out acute MI.  Conversely, a hs-cTnT>0.005 ug/L had a positive predictive value of only 21.8% for ruling in an acute MI. 

These results support the use of a single negative hs-cTnT measured at least 3 hours after symptom onset and a nonischemic ECG to rule out AMI in adult ED patients with chest pain. 

Man with an acute myocardial infarction (MI)

Reference:

Pickering JW et al. Rapid rule-out of acute myocardial infarction with a single high-sensitivity cardiac troponin T measurement below the limit of detection: A collaborative meta-analysis. Ann Intern Med.  2017 Apr 18; [e-pub].