No 11 - Stop MOANing about MIs and ACT

Tldr

Chest pain caused by your heart can be divided into 4 groups along a spectrum of disease - Stable Angina, Unstable Angina, non-ST elevation MI and ST elevation MI.

UA, NSTEMI and STEMI are grouped as ACS - Acute Coronary Syndrome.

ACS is currently treated by the acronym MONA or MONAC or MONAT in most cases. Morphine, Oxygen, Nitrates, Aspirin, Clopidogrel and Ticagrelor.

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Today I have listened to 2 fantastic podcasts - “The Resus Room” update on ACS and “St.Emlyn’s Podcast” on Troponins.

https://www.theresusroom.co.uk/all-content/

https://www.stemlynsblog.org/podcasts/

I expect most healthcare students and professionals who haven’t been living in a cave for the last 7 years are probably already aware of both of these… but if you have been living in a cave then you really should check them out.

ACS is the bread and butter of medical student learning but it is still a really interesting topic, and no matter how many articles, lectures, podcasts and ALS courses I complete, I always feel like there is more to learn.

The Ischeamic Heart Spectrum

Angina = heart pain but no damage. It’s a warning sign that the arteries supplying oxygenated blood to your heart are not as healthy as they used to be.

Stable angina = pain when you are doing something, like walking up a hill and your heart is working harder. The pain goes away if you take a break for 30 seconds or so. It also goes away if you use a GTN spray (nitrates), which dilate (widen) the arteries of your heart and allow more blood to flow.

Unstable angina = the heart arteries are too narrow for your heart to get enough oxygen flowing to it, but it can cause pain even when you aren’t doing anything. This is a big red flag warning sign that you need to see a doctor ASAP because although your heart isn’t being injured yet, it might be very soon.

The non-ST elevation and ST elevation MI’s just mean that the ECG (heart tracing) has got a particular shape or hasn’t. The ST elevation is known as the “tomb stone sign” because it looks similar and 20 years ago it was the common outcome if a patient had this on their ECG and chest pain. Nowadays we are much better at saving lives!

You can think of these 4 groups along a continuum with Stable angina on one sign and as the arteries get narrow and narrower ST-Elevation heart attacks (MIs) on the other side. The actual pathophysiology is quite complicated but the summary is unhealthy lifestyles and bad genetics make your arteries “furr up” and then block.

How do you tell the difference between Angina and an NSTEMI?

Troponins. Normally 2 tests at least an hour apart and if the level goes up then you are possibly having an MI and if the level stays the same or goes down then you probably aren’t. It’s a little more complicated by this and I thoroughly recommend listening to the podcasts if you want the details.

How do you treat stable Angina?

Rest, GTN spray, stop smoking, do more exercise, take your statins, eat a healthy diet and hope that you have good genes. Also, speak to your GP if you are getting chest pain regularly or if you are just worried at all.

How do you treat ACS?

MONA or MONAC or MONAT

The NNT.com website is a medical geeks dream, it really is!

https://www.thennt.com/lr/acute-coronary-syndrome/ - if you really want to be cool then you can memorise exactly which of the signs and symptoms are actually predictive of an MI!

https://www.thennt.com/nnt/aspirin-for-major-heart-attack/

Aspirin has a number needed to treat of 47. Every 47 people who you think have ACS and you give them 300mg of Aspirin, then you have saved 1 person’s life who would otherwise have died!

Aspirin by these numbers is one of the most effective life savings medications that we have.

If someone is having chest pain that lasts more than 10 minutes then give them 300mg of Aspirin straight away.

https://www.thennt.com/nnt/clopidogrel-added-to-aspirin-during-and-after-a-coronary-event-or-stenting/

Adding Clopidogrel 300mg to the 300mg Aspirin had an NNT of 27. So for 27 people given both there was 1 fewer MI.

https://www.thennt.com/nnt/ticagrelor-compared-clopidogrel-acute-coronary-syndrome-stable-coronary-artery-disease/

Some trusts use Ticagrelor instead of Clopidogrel… its probably about the same. Some cardiologists believe it might be better.

https://www.thennt.com/nnt/opiate-analgesia-acute-abdominal-pain/

Morphine has an NNT of 5 in abdominal pain - the site didn’t have a review of ACS pain. This doesn’t really matter though because if you tell an ambulance crew you have chest pain you will most likely get 10mg of IV morphine.

You will also probably get Metoclopramide (NNT = 7.8 for post op nausea - https://pubmed.ncbi.nlm.nih.gov/23015617/) because big doses of morphine can make some people feel sick and vomit, which you don’t want.

Interestingly The NNT.com site didn’t have Metoclopramide or GTN on it. I couldn’t actually find an NNT for GTN but it probably helps most people with the pain however, unfortunately it doesn’t actually any more likely to keep them alive. Symptomatic benefit only. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3527093/

Oxygen should only be given if someone has a saturation below 94% otherwise it was found to be harmful. https://www.thennt.com/nnt/oxygen-therapy-patients-acute-myocardial-infarction/

Finally - the end

This was a very short summary of ACS and its management. ACT don’t MOaN is my new favourite phrase because while Morphine/ Metoclopramide, Oxygen and GTN might feel like we are helping they aren’t going to keep the patient alive, so ACT first with Aspirin and Clopidogrel/ Ticagrelor then you can MOaN once you have saved their life.

As always, if you want to leave a positive comment, point out what I have got wrote or just send me some more interesting links then please leave a comment below. If you have found this article useful then please share it far and wide.