Return of the MACS

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A middle aged man who is normally fit and well presents following 'indigestion' earlier that day which has settled.  He says his indigestion was a burning pain in the middle of his chest which did not move anywhere.  He blames it on overdoing it the night before with food and alcohol.  He looks and feels well now and only came to the department because his father had a heart attack at a similar age.  His ECG is normal.  His Troponin I is 10,000.  The patient is amazed as he is told he's had a heart attack, "but it didn't feel like a heart attack looks on the TV".

First things first - what is an myocardial infarcation?  We're now on our third universal definition of MI and it's important to note the 5 types of MI:

  1. Unstable plaque rupture or coronary dissection
  2. Supply/demand mismatch - such as arrhythmia or anaemia
  3. Sudden cardiac death that includes signs and symptoms of myocardial ischemia, such as ECG changes, but which produces death before a blood sample can be obtained or when death occurs during the lag period before serum markers appear in the blood
  4. PCI related
  5. CABG related

You'll notice nowhere in the definition of MI or in the types of MI does it mention the character of pain.  If we hear the words 'cardiac chest pain' we will all imagine crushing central chest pain radiating to the left arm with pins and needles.  

This is where the work of Professor Richard Body at the University of Manchester is so interesting.  The Manchester Acute Coronary Syndrome (MACS) Decision Tool was discussed in the ACS Take Aurally podcast.  As part of this work the five most sensitive features of the history for ACS were not the pain itself but if it was associated with:

  1. Diaphoresis
  2. Vomiting
  3. Pain radiating to RIGHT shoulder  
  4. Worsening angina
  5. Hypotension

As I mentioned in the #FYEO blog post on Red Flags I find this work fascinating due to it being paradigm shifting.  Whenever I mention this to students it very often produces a 'mind blown' moment.  This is important.

Learning Points

  1. Chest pain is chest pain.  Whether it's 'indigestion', a 'twinge', an 'ache' it needs to be worked up as chest pain.  I talked about this in my presentation on red flags.
  2. Gastritis and GORD is a not a diagnosis for a junior to make; nor is it an ED diagnosis to make without ruling out more serious causes.  Maybe if the patient is well known to have GORD/Barrett's Oesophagus and gives a compelling history but even then the more serious causes have to be ruled out.
  3. There are five kinds of MI.