Monday, October 31, 2016

Is troponin really becoming a lousy test?

Just a quick reminder this week regarding the use of troponin. This is one of the most abused tests in Emergency Departments these days.  The hs Troponins seems to be overtly sensitive that might lead to unnecessary admissions. Here are a few caveats with troponin:

1. Do a history first, followed by a physical exam and then ECG. Only after that, send a troponin if you are concerned about the possibility of ACS. 

DO NOT ORDER TROPONIN FOR EVERYONE WALKING IN WITH CHEST PAIN

2. Remember that there a  plenty of other reasons to have a positive troponin besides ACS. To name a few - PE, Heart Failure, Sepsis, Renal Failure, Stroke, Tachycardia, Infiltrative Heart Disease, Myopericarditis.

A RAISED TROPONIN DOES NOT ALWAYS EQUAL ACS. TROPONIN IS A MARKER OF ANY MYOCARDIAL INJURY, NOT JUST ISCHEMIA. 

3. STEMI does not need a troponin. Focus on rapid Reperfusion (Thrombolytics or PCI). Troponin is done to differentiate between NSTEMI and USA (Unstable Angina).




4. Discharging someone with a single negative troponin is high risk business (unless it was drawn 6 hours after the onset of symptoms). Whenever possible, get two serial troponins to see if there is any significant rise form the baseline. However, serial sampling of hs troponin at 0 and 2 hours can safely rule-out of STEMI and NSTEMI. 

In case, you happen to discharge home a patient with two negative troponins, document why are you doing that because it can still be Unstable Angina. 

5. Troponin might take 6-12 hours to rise from the onset of symptoms and stays elevated upto 2 weeks. Document your concerns while sending these cardiac biomarkers.


Attorneys focus on the documentation of HPI, documentation of ECG findings and Medical Decision Making with appropriate reasoning before settling the case. We are going to cover these bits next week. 


BOTTOMLINE: I think troponin is still a great test, if done with caveats. However, over the last two decades, it has become extremely sensitive and thus non-specific (like d-dimer for PE). 



Further Reading: 





Author:

              
     Lakshay Chanana
     
     Speciality Doctor
     Northwick Park Hospital
     Department of Emergency Medicine
     England

     @EMDidactic



                         

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