What should you call that elevated troponin?

Author

Robert Oubre, MD
December 10, 2022 • Estimated Reading Time: 7 minutes

What should you call that elevated troponin?

This is NOT taught and has important downstream impacts.

Understand it in 2 minutes:

The problem?

  • Most don’t understand how to interpret troponins

  • Most don’t understand the actual definition of an infarction

  • Proper diagnosis (& documentation) ➡️ impacts clinical decisions and quality metrics

First, pay close attention to the three I-words:

  1. Injury

  2. Ischemia

  3. Infarction

It is easy to mix them up and lose track. Pay close attention their distinctions.

Two things must be present for an acute Myocardial INFARCTION

  1. Acute myocardial INJURY

  2. Signs or symptoms of ISCHEMIA 

(Notice the OR here)

Let’s break those down.

1 / What is myocardial INJURY?

Myocardial Injury = Elevated troponin (above 99% upper range limit)

ACUTE myocardial injury = A fluctuation of troponins by 20%. Whether this be:

  • A rise of 20% (with at least one elevated) OR

  • A fall of 20% if at least initial was elevated

What if elevated but does not change by 20%? Will answer this later.

2 / What are Signs & Symptoms of ISCHEMIA?

Symptoms

  • Angina

  • Anginal Equivalents (SOB, diaphoresis, nausea, lightheadedness)

**** These symptoms must be documented AS ANGINAL EQUIVALENTS****

  • Syncope

  • Flash pulmonary edema

  • Palpitations

  • Cardiac arrest

Signs

  • ST elevation or depression

  • New flipped T wave

  • New LBBB

  • New pathological Q waves

  • NM stress with new loss of viable myocardium (NOT scar)

  • New ventricular wall motion abnormality

  • Identification of coronary thrombus on LHC or autopsy

3 / What are the types of INFARCTions?

Type 1 (STEMI vs NSTEMI)

  • Acute coronary artery occlusion due to plaque disruption

  • Treatment –> dissolve clot / open blockage

(Reminder: Must have Injury + Ischemic signs or symptoms)

Type 2 (NSTEMI)

  • Imbalance between myocardial oxygen supply and/or demand results in INFARCTion

  • Treatment –> relieve demand / non-CAD factors

(Reminder: Must have Injury + Ischemic signs or symptoms)

Other types of infarctions:

  • Type 3 = Sudden death without biomarkers

  • Type 4a = PCI related AMI

  • Type 4b = Due to stent thrombosis

  • Type 4c = Stent re-stenosis

  • Type 5 = CABG related.

Will not go into detail about these.

4 / What about elevated troponins alone?

That is myocardial INJURY w/o ischemia (thus not infarction)

20% rise / fall? = Acute myocardial Injury

  • Ex: Acute CHF, myocarditis, etc.

No 20% rise / fall? = Chronic myocardial injury

  • Ex: CKD, structural heart disease, etc.

  • This is your “troponin leaks”

You may find this in EPIC as “Non ischemic (non-traumatic) myocardial injury”

Acute & Chronic code to the same diagnosis so don’t get hung up on it.

This IS NOW a CC (Comorbid Condition) which carries significant weight. This was not the case several years ago.

5/ What is Demand Ischemia?!

This technically DOES NOT exist in the 4th universal definition of MI.

but it is still a codable diagnosis.

The definition is not clear, and guidance is conflicting and seems ever changing.

I’ll use this if:

  • There is a setting of supply / demand mismatch

  • But have ischemic signs or symptoms WITHOUT injury (but not both because then it’s a Type 2 NSTEMI)

So, every Type 2 NSTEMI has demand ischemia, but not every demand ischemia is a Type 2 NSTEMI.

In summary:

  1. Acute Myocardial Injury = 20% change of elevated troponins

  2. Infarct = Injury + Ischemic signs or symptoms

  3. REMOVE “Troponemia”, “troponin leak”, “troponitis” & “elevated troponins” from your vocabulary (unless you’re using them as a place holder for further specification such as on admit)

  4. Demand Ischemia = ischemia without injury in setting of supply/demand mismatch

Question / Answers + Further Discussion

What if a patient presented several days after they had a story concerning for an Acute MI?

  • An acute MI “lasts” for 28 days for coding purposes. If there are new ischemic signs on presentation, the patient can be considered to have an acute myocardial infarction within 28 days of that event. You MUST specifically document that you suspect the prior event was such.

  • By the way, if a patient has another MI after 28 days, it’s considered a recurrent MI

  • If a patient develops another true myocardial infarction event within 28 days, it’s considered a Subsequent infarction (or reinfarction).

  • Even cardiologist mix up these two definitions! For more info go to:Fourth Universal Definition of Myocardial Infarction (2018) Search the term “28 days” and this will bring you right to the section.

You mentioned downstream impacts. What are they?

  • Be mindful to accurately document Type 1 vs Type 2. Why?

  • CMS tracks and publicly reports 30-day readmissions, 30-day mortality, AND extended stays for Acute Myocardial Infarctions. This does not include Type 2 MI’s.

  • If readmissions are high, your hospital will get dinged and will lose money (sometimes in the form of literally paying it back).

What about the plateau that happens at peak troponin levels?

  • This is a great question! The 4th universal definition actually does not perfectly define a time period of which you should see a change as there is much variably.

  • The upslope is steeper than the downslope, and you should see a change within 1 - 3 hours.

  • The downslope is much more variable. With more time, such as 12 - 18 hours, I would suspect you should see a change.

What about CK-MB?

  • CK-MB is less sensitive and less specific, so this is not used often anymore unless troponin is not available.

What about an absolute troponin value?

  • The 4th universal definition does not define a troponin absolute value that by itself defines acute myocardial injury, as unusual as that sounds.

  • The only reference to such is post-PCI MI’s where a troponin value of >5 times the 99th percentile URL is needed.

Type II NSTEMI’s are not your principal diagnosis

  • Because Type II NSTEMI’s are a result of supply / demand mismatch, the NSTEMI is going to be DUE TO something else. Make sure to specify in your documentation what the Type II NSTEMI is “due to.”

That’s all for now. I hope that’s helpful.

Please feel free to reach out and ask questions as they help inspire future issues!

Cheers,

Robert

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