Cardiac enzymes - how do you guys use it and what do you prefer?

[pinipig523]

So, I've been using Trop I since residency but at my new job, we have options for CK and CKMB. Do you guys use these and if so, how do you use it in conjunction with Trop I?

I know that CK is found everywhere and not just cardiac whereas CKMB is a bit more cardiac specific.

Thanks!

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[name?]

Our cardiologists frequently disregard an elevated MB if CTNI is negative and appropriate time has passed. In general, the index (MB/total CPK) is supposedly more useful than the MB alone as they can both be elevated in rhabdo, but the index should be less then 2.5%(5% in some places).

 

[Doctor Bob]

Our chest pain protocol used to be Trop I and CKMB, but recently we dropped the CKMB. In our observation unit we also only check serial troponins.

 

[Cerberus]

I've caught several NSTEMIs with positive CKMBs and Negative trops. If I have someone with a good story, negative trops but positive CKMBs with a ratio pointing to cardiac etiology, I'll be more aggressive than I am with just a chest pain r/o.

 

[turkeyjerky]

I've caught several NSTEMIs with positive CKMBs and Negative trops. If I have someone with a good story, negative trops but positive CKMBs with a ratio pointing to cardiac etiology, I'll be more aggressive than I am with just a chest pain r/o.

Interesting, did they have definitive follow up proving it was actually an NSTEMI?

 

[Cerberus]

Interesting, did they have definitive follow up proving it was actually an NSTEMI?

Yeah, they were confirmed either with repeat trops or, in one case, a repeat EKG which went from T wave inversions to a STEMI. I can't say I've seen this happen too often. Everyone getting cardiac enzymes gets a CKMB at my shop and in the time I've been here I've only had it happen a handful of times.

 

[Groove]

Virtually all of our cardiologists at home institution and tertiary care hospitals that I speak with while moonlighting disregard all assays other than Troponin. Their reasoning is that Trop I is more sensitive and technically should be present sooner than a CK-MB elevation. I never order CKMB or Myo. I just don't see how it changes my clinical management. If I have high clinical suspicion for ACS, then I'll work up and dispo as such regardless of negative enzymes. The only time I've been impressed with the "enzyme triad" was when an outside EP transferred a chest painer for cards eval to us and had negative Trop, CKMB but a positive myoglobin. Second set of Trop was positive and ended up with NSTEMI but as you can imagine, without EKG changes and definitive enzyme changes and an equivocal presentation, it's virtually impossible to diagnose NSTEMI on a myo alone, hence I don't bother with them because if I'm concerned for ACS or other cardiac emergency, I want a cardiologist to see them or I want them admitted for ACS rule out.

So, I'm sure there are exceptions with the wealth of experience on here... but can't see how the other enzymes would really change my management in 99% of cases.

I really haven't found a cards guy who does anything but poo poo the CKMB.

 

[RustedFox]

No CK-MB at my new shop. Trops only.

I asked my favorite cardiologist back in residency this same question not long ago. He said - "Unless the CK-MB is over say... 6.... then I ignore it altogether."

 

[Arcan57]

No CK-MB at my new shop. Trops only.

I asked my favorite cardiologist back in residency this same question not long ago. He said - "Unless the CK-MB is over say... 6.... then I ignore it altogether."

My old shop's cardiologist were big on CK-MB in pt's with renal failure (although they were also eager to attribute Trop-I's in the 1.75 range to renal insufficiency). I like CK-MB because of the 2-hr delta MB r/o. I haven't seen a Trop paper that had that quick a turn-around time.