Does Troponin add anything to Screening for Blunt Cardiac Injury?

There has been recent interest in investigating Troponin levels in screening for BCI following significant mechanism to the chest.  Standard practice is to obtain a EKG as a screening test with any deviation from normal sinus rhythm or sinus tachycardia considered a positive screen.  These patients are subsequently admitted for telemetry monitoring and ekgs every 8 hours in order to observe for arrhythmia or new hemodynamic changes.  The most recent Trauma EAST guidelines recommend the addition of a troponin level to a negative ECG as there may be a significant subset of patients who are at risk that are not caught on initial screening ECG.  This update seems primarily based on a study in 2001 by Salim augmented by a study in 2003 by Velmahos. 

 

As per the East summary:

"The incidence of significant BCI in their study was 13%, which they defined as cardiogenic shock, arrhythmia requiring treatment, posttraumatic structural defects, or unexplained hypotension. Importantly, 5 of 67 patients with normal initial ECG result had a positive result for troponin and clinically significant BCI defined by hypotension, arrhythmia, decreased cardiac index, and/or need for treatment. An abnormal cTnI level was defined as greater than 1.5 ng/mL."

 

The authors of the EAST guidelines conclude that a normal ECG with an elevated Troponin should be admitted for monitoring with a Level II level of evidence. 

 

The AAST guidelines, also from 2012, offer a softer recommendation that troponin "may" be useful in addition to a normal ECG. 

 

As far as practice at Cook County Hospital, at this time the question of whether a troponin level should be routinely added to an ECG to screen for BCI in appropriate patients is still under investigation.

 

1. Velmahos G, Karaiskakis M, Salim A, et al.. Normal electrocardiography and serum troponin I levels preclude the presence of clinically significant blunt cardiac injury. J Trauma. 2003; 54: 45–51.
2. Salim A, Velmahos G, Jindal A, et al.. Clinically significant blunt cardiac trauma: role of serum troponin levels combined with electrocardiographic findings. J Trauma. 2001; 50: 237–243.
3. http://www.east.org/resources/treatment-guidelines/blunt-cardiac-injury,-screening-for

from Dr. Shalako Denison