Acute Coronary Syndrome

Question 1

What is ACS usually a cause of?

Answer 1

A thrombus from an atherosclerotic plaque blocking a coronary artery

Question 2

Why are anti-platelet medications mainstay of treatment in ACS?

Answer 2

When a thrombus forms in a fast flowing artery it is made up mostly of platelets

Question 3

What are the three types of ACS?

Answer 3

Unstable Angina
ST Elevation Myocardial Infarction (STEMI)
Non-ST Elevation Myocardial Infarction (NSTEMI)

Question 4

What symptoms suggest ACS?

Answer 4

Chest pain - the classical presentation can be considered in terms of the SOCRATES mnemonic:

Site - Central/left sided

Onset - Often sudden

Character - Crushing (‘like someone is sitting on your chest’)

Radiation - Left arm, neck and jaw

Associated symptoms - Nausea, sweating, clamminess, shortness of breath, sometimes vomiting or syncope

Timing - Constant

Exacerbating/relieving factors - Worsened by exercise/exertion and may be improved by GTN

Severity - Often extremely severe

Question 5

What should you do if a patient presents with possible ACS?

Answer 5

Perform an ECG

Question 6

What is a myocardial infarction?

Answer 6

When there is a blockage in blood supply to the heart that cuts off oxygen to the heart, causing the heart muscle to die

Most MIs are due to atherosclerosis

Question 7

How can a STEMI be diagnosed?

Answer 7

ST elevation or new left bundle branch block on an ECG

Question 8

What should you do is ACS is suspected but the ECG shows no ST elevation?

Answer 8

Perform troponin test

Question 9

How can NSTEMI be diagnosed?

Answer 9

Raised troponin levels
ECG changes - ST depression or T wave inversion or pathological Q waves

Question 10

What is the diagnosis if ACS is suspected but troponin levels and ECG are normal?

Answer 10

Unstable angina or another cause such as MSK chest pain

Question 11

What is the treatment in acute STEMI?

PROCEDURES

Answer 11

Patients with STEMI presenting within 12 hours of onset should be discussed urgently with local cardiac centre for either:

Primary PCI (if available within 2 hours of presentation and within 12 hours of symptom onset)
Thrombolysis (if PCI not available within 2 hours)

Question 12

Acute NSTEMI treatment

Answer 12

B – Beta-blockers unless contraindicated

A – Aspirin 300mg stat dose

T – Ticagrelor 180mg stat dose (clopidogrel 300mg is an alternative if higher bleeding risk)

M – Morphine titrated to control pain (IV morphine/diamorphine)

A – Anticoagulant: Fondaparinux (unless high bleeding risk)

N – Nitrates (e.g. GTN) to relieve coronary artery spasm

Give oxygen only if their oxygen saturations are dropping (i.e. <95%).

Start antithrombin therapy such as treatment dose low molecular weight heparin or fondaparinux if they are for an immediate angiogram

Patients with high 6 month risk of mortality should be offered an angiogram within 96 hours of symptom onset.

Question 13

What is used to assess for PCI in NSTEMI?

Answer 13

GRACE score

Question 14

What does the GRACE score tell us?

Answer 14

6 month risk of death or repeat MI after having an NSTEMI

Question 15

What are the different outcomes of a GRACE score?

Answer 15

<5% Low Risk
5-10% Medium Risk
>10% High Risk

Question 16

Who is considered for early PCI (within 4 days of admission) to treat underlying coronary artery disease?

Answer 16

Medium or high risk

Question 17

What are the complications of MI?

Answer 17

THINK: DREAD

Death
Rupture
Edema (heart failure)
Arrhythmia and Aneurysm
Dressler’s Syndrome

Question 18

What is dressler’s syndrome?

Answer 18

AKA Post-myocardial infarction syndrome.

It usually occurs around 2-3 weeks after an MI.

It is caused by a localised immune response and causes pericarditis

It is less common as the management of ACS becomes more advanced.

Question 19

How does Dressler’s syndrome present?

Answer 19

Pleuritic chest pain
Low grade fever
Pericardial rub on auscultation.

Question 20

How is dressler’s syndome diagnosed?

Answer 20

ECG (global ST elevation and T wave inversion), echocardiogram (pericardial effusion) and raised inflammatory markers (CRP and ESR).

Question 21

What is the management of Dressler’s syndrome?

Answer 21

NSAIDs (aspirin / ibuprofen) and in more severe cases steroids (prednisolone).

May need pericardiocentesis to remove fluid from around the heart

Question 22

Secondary prevention (6 A’s) of MI

Answer 22

Aspirin 75mg once daily

Another antiplatelet: e.g. clopidogrel or ticagrelor for up to 12 months
Atorvastatin 80mg once daily

ACE inhibitors (e.g. ramipril titrated as tolerated to 10mg once daily)

Atenolol (or other beta blocker titrated as high as tolerated)

Aldosterone antagonist for those with clinical heart failure (i.e. eplerenone titrated to 50mg once daily)

Question 23

Secondary prevention lifestyle

Answer 23

Stop smoking
Reduce alcohol consumption
Mediterranean diet
Cardiac rehabilitation (a specific exercise regime for patients post MI)
Optimise treatment of other medical conditions (e.g. diabetes and hypertension)

Question 24

How many types of MI are there?

Answer 24

4

Question 25

What is a type I MI?

Answer 25

Traditional MI due to an acute coronary event

Question 26

What is type II MI?

Answer 26

Ischaemia secondary to increased demand or reduced supply of oxygen (e.g. secondary to severe anaemia, tachycardia or hypotension)

Question 27

What is type III MI?

Answer 27

Sudden cardiac death or cardiac arrest suggestive of an ischaemic event

Question 28

What is type IV MI?

Answer 28

MI associated with PCI / coronary stunting / CABG

Question 29

What is troponin and when is it released?

Answer 29

A myocardial protein released into the bloodstream when cardiac myocytes are damaged. Serum levels typically rise 3 hours after myocardial infarction begins.

Question 30

What does a low troponin level mean in regards to ACS?

Answer 30

Definitely no myocardial cell death. The patient is not having an MI although they may be experiencing unstable angina.

Question 31

What does a mildly raised troponin level mean in regards to ACS?

Answer 31

These patients usually need a 6-12 hour repeat test. If repeat troponin is raised on the repeat they are having an MI. If repeat troponin is stable or falling then they are unlikely to be having an MI.

Question 32

What does a highly raised troponin level mean in regards to ACS?

Answer 32

MI confirmed (be aware of the possibility of a Type 2 MI)

Question 33

What is a rise in troponin related to?

Answer 33

A rise in troponin is consistent with myocardial ischaemia as the proteins are released from the ischaemic muscle. They are non-specific, meaning that a raised troponin does not automatically mean ACS.

Question 34

Other than ACS, what can cause a raise in troponin levels?

Answer 34

Chronic renal failure Sepsis Myocarditis Aortic dissection Pulmonary embolism Pericarditis Myocarditis Arrythmias Defibrillation Acute heart failure Pulmonary embolus Type A aortic dissection Chronic kidney disease Prolonged strenuous exercise

Question 35

What is the treatment for STEMI? Medication

Answer 35

Targeted oxygen therapy (aiming for sats >90%) Loading dose of PO aspirin 300mg Note that some hospital protocols will also call for a loading dose of another anti-platelet agent such as clopidogrel (300mg) or ticagrelor (180mg) Sublingual GTN spray - for symptom relief IV morphine/diamorphine - in addition this causes vasodilation reducing preload on the heart

Question 36

What five drugs should al patients be started on post-MI?

Answer 36

Aspirin 75mg OM + second anti-platelet (clopidogrel 75mg OD or ticagrelor 90mg OD) Beta blocker (normally bisoprolol) ACE-inhibitor (normally ramipril) High dose statin (e.g. Atorvastatin 80mg ON)

Question 37

Who should all patients be referred to post-MI?

Answer 37

Cardiac rehab

Question 38

What should all patients have post-MI?

Answer 38

ECHO performed to assess systolic function and any evidence of heart failure should be treated.

Question 39

What is an echocardiogram?

Answer 39

A type of ultrasound. Checks structure of heart and surrounding vessels, analysing how blood flows through them, and assessing the pumping chambers of the heart.