63 year old with "good story for ACS" but negative troponins.....

 This was texted to me from a former resident, while working at a small rural hospital, with the statement:

"I can’t convince myself of anything here, but he’s a 63-year-old guy with prior stents and a good story for ACS."  (Chest pain or discomfort)

What do you think?

Here was my response:

"Suspicious for inferior posterior OMI.  Get serial ECGs"

He then sent a previous from 4 years prior:

"This is totally normal, which confirms that the first EKG does indeed represent OMI"

Then the patient's chest pain resolved and he recorded another:

The ST depression in aVL is gone and the T-waves are less hyperacute, so this is consistent with reperfusion.

He did not think the cardiologist at the referral institution would agree.

I said "give aspirin, heparin, and troponins will be positive."

The total duration of chest pain was 30-45 minutes.

The first trop returned at 15 ng/L (URL for this assay is 22 ng/L)  I do not know what assay it is, nor (obviously) what studies have been done on it in ACS.

I said to get the 2nd trop at one hour, believing it would rise significantly.  

But the repeat trop was only 18 ng/L.  A delta of 3 ng/L at one hour does not necessarily rule out MI, and it very dependent on lots of factors, especially on which assay is being used.  A delta of 3 ng/L definitely would not rule-in MI for any assay, but it does raise the possibility that further measurements would result in a 4- or 6-hour troponin above the URL and thus make the diagnosis of acute MI. 

I said that this is unstable angina until proven otherwise.

He was able to transfer the patient using my recommendation.

A cardiology note said: "EKG without ischemic changes.  Troponins negative."

Outcome

The only followup we got was that the patient is undergoing Coronary Bypass (CABG) of LAD, 2nd Obtuse Marginal, and Left Posterolateral coronaries.

We don't know if he had a stress test, a CT Coronary angiogram, or they just decided to do an angiogram.  And we don't have the exact results of the angiogram, but it was clearly positive for very serious acute change in the coronaries.  Thus, Unstable Angina.

The sender asked me to explain:

"Please describe the ekg. Why does it look concerning to us? The best I can say is the sagging T waves in V3 and V4 but otherwise it’s very nonspecific ST-T wave changes.  Even compared to his old one, I think most people would still just say there are ST – T wave changes that are non-specific."

My answer:

"There is slight ST elevation in inferior leads with terminal QRS distortion. That is to say, the S-wave is obliterated in those leads. There is reciprocal, slight ST depression in AVL with a down up T-wave.  There is slight ST depression in V2."

"Finally, it is often impossible to describe why I think it is OMI.  I recognize EKG’s like faces. You cannot say why a photo of Paul looks like Paul, but it does."

"As you can see, the queen agrees that is OMI with high confidence (see below). I sent it to Pendell, and he said OMI with low confidence without any other information.  I’m not sure if you know who the queen is. That is the AI robot that we trained to diagnose OMI."

I sent the first ECG to the Queen of Hearts (PMcardio OMI), and here is the verdict:

Finally,  a nice note from the sender:

"I think I maybe told you this, but I hated EKGs as a resident. But thanks to you, I feel much more confident. Thank you for your work with the artificial intelligence and the blog to make people better at this. It has for sure helped me."