Acute coronary syndrome (ACS)

Question 1

What causes ACS? What is the difference in the pathogenesis of the three conditions?

Answer 1

Disruption of atheromatous plaque is the pathophysiologic basis of ACS. Following plaque
rupture and the initiation of thrombotic cascade, myocardial ischaemia and injury sets in
and lead to differing clinical forms of ACS.

UA and NSTEMIs are associated with partially occlusive thrombus - still some blood flow.

STEMIs typically result from occlusive thrombus.

Question 2

What cardiac markers do we look at for diagnosing ACS?

Answer 2

Cardiac troponins

Question 3

What level of troponin is indicative of myocardial damage??

Answer 3

> 100 (normal = <30)

Question 4

How does troponin levels differ between the three conditions?

Answer 4

UA - negative
NSTEMI - postiive
STEMI positive

Question 5

How can we distinguish between a STEMI and NSTEMi

Answer 5

NSTEMI - ST segment depression and/or T wave inversion

STEMI - ST segment elevation

Question 6

What is the acute (usually pre-hospital management) of suspected ACS?

Answer 6

Aspirin 300mg PO STAT
Morphine 5-10mg IV PRN
Antiemtic e.g. metoclopramide 10mg IV
GTN spray s/l PRN
Antithrombin therapy - fondaparinux
Oxygen if needed

Question 7

How might we manage a diabetic presenting with a suspected ACS?

Answer 7

Consider a dose adjusted insulin infusion with regular monitoring of blood glucose levels.

Question 8

What is the recommended antithrombin therapy in ACS?

Answer 8

Fondarparinux in patients who do not have a high bleeding risk. Give 2.5mg s/c STAT and then once daily.
Offer UFH as an alternative, if patients are likely to undergo CABG within 24 hours or in renal impairment.

Question 9

What is the GRACE score?

Answer 9

An assessment tool to determine the risk of future adverse cardiovascular events using an established risk scoring system - predicts 6-month mortality. We use the outcome to guide how the patient should be managed.

Question 10

A GRACE score of >3-6% means what?

Answer 10

Intermediate risk

Question 11

A GRACE score of >6-9% means what?

Answer 11

High risk

Question 12

A GRACE score over 9 means what?

Answer 12

Highest risk

Question 13

A GRACE score <3 means what?

Answer 13

Low risk

Question 14

What signs and symptoms are associated with ACS?

Answer 14

Chest pain/discomfort/pressure

Dizziness/light-headedness, SOB and sweting

Question 15

When should eplerone be given?

Answer 15

Aldosterone antagonist, should be initiated in any patient with evidence of cardiac failure (heart failurE)

Question 16

How do we manage diabetes in actue myocardial infarction?

Answer 16

All known and newly diagnosed patients with diabetes should have regular
glucose monitoring and should be maintained within the strict targets, if needed
initiate treatment with intravenous insulin and glucose for at least 24 hours.

Existing oral hypoglycaemic agents should be stopped while intravenous Insulin is
being given.

Question 17

What is fondaparinux? What is its MOA?

Answer 17

Fondaparinux sodium is a synthetic pentasaccharide that inhibits activated factor
X

Question 18

How long should fondaparinux be given for?

Answer 18

2- 8 days or until discharge (whichever is sooner).

Question 19

If early angiography is planned, cannot give the patient fondaparinux - what is a suitable antithrombin alternative?

Answer 19

UFH

Question 20

At what point in fondaparinux CI in renal impairment? What should be used instead?

Answer 20

Should not be used in patients with an eGFR <20ml/min. Use UFH instead.

Question 21

When should we consider using Tirofiban?

Answer 21

Consider Tirofiban in ACS patients who have ECG evidence of ischaemia,
especially with on-going chest pain and the patient cannot be imminently taken to
cardiac cath lab for coronary angiography.

Question 22

What STAT antiplatelet therapy should be given to a patient with ACS?

Answer 22

300mg Asprin

300mg Clopidogrel - NICE. Local guidelines day 600mg

Question 23

When might thrombolysis be indicated?

Answer 23

When primary percutaneous coronary intervention cannot be provided within 120 minutes of
ECG diagnosis, patients with an ST-segment-elevation acute coronary syndrome should receive
immediate (prehospital or admission) thrombolytic therapy.

Question 24

What drugs should be offered to all patients following an acute MI (STEMI/NSTEMI), assuming there are no CI?

Answer 24

ACEi
Dual antiplatelet therapy
Beta blockers
Statin

Question 25

How should the ACEi be introduced and titrated?

Answer 25

Start at low dose and titrate upwards in short intervals (every 12-24 hours) until max tolerated or target dose is achieved.

Question 26

What monitoring is required for ACEI?

Answer 26

Base line renal function, U&Es, BP. After each dose increment and then in 1-2 weeks. Then every 3 months.

Question 27

What is the target bisoprolol dose following ACS?

Answer 27

10mg OD (Start on 2.5mg and titrate up)

Question 28

What is the target ramipril dose following ACS?

Answer 28

10mg OD (may be in divided doses, 5mg bd)

Question 29

What is an exercise tolerance test?

Answer 29

Exercise tolerance testing (also known as exercise testing or exercise stress testing) is used routinely in evaluating patients who present with chest pain, in patients who have chest pain on exertion, and in patients with known ischaemic heart disease.

Question 30

What b blocker does NICE advise in ACS?

Answer 30

Atenolol - starting dose 25mg increased to 50mg.

Although a cardioseletive BB like bisoprolol might be preferred as patients are at risk of HF anyway

Question 31

Patients taking dual antiplatelet therapy may require something for GI protection, what would you advise?

Answer 31

Not omeprazole - interacts with clopidogrel and reduces its antiplatelet effects.
Ideally, avoid all PPI
H2 receptor antagonist is the drug of choice - Ranitidine 300mg BD.