Acute coronary syndrome (ACS) Flashcards
What causes ACS? What is the difference in the pathogenesis of the three conditions?
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.
What cardiac markers do we look at for diagnosing ACS?
Cardiac troponins
What level of troponin is indicative of myocardial damage??
> 100 (normal = <30)
How does troponin levels differ between the three conditions?
UA - negative
NSTEMI - postiive
STEMI positive
How can we distinguish between a STEMI and NSTEMi
NSTEMI - ST segment depression and/or T wave inversion
STEMI - ST segment elevation
What is the acute (usually pre-hospital management) of suspected ACS?
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
How might we manage a diabetic presenting with a suspected ACS?
Consider a dose adjusted insulin infusion with regular monitoring of blood glucose levels.
What is the recommended antithrombin therapy in ACS?
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.
What is the GRACE score?
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.
A GRACE score of >3-6% means what?
Intermediate risk
A GRACE score of >6-9% means what?
High risk
A GRACE score over 9 means what?
Highest risk
A GRACE score <3 means what?
Low risk
What signs and symptoms are associated with ACS?
Chest pain/discomfort/pressure
Dizziness/light-headedness, SOB and sweting
When should eplerone be given?
Aldosterone antagonist, should be initiated in any patient with evidence of cardiac failure (heart failurE)
How do we manage diabetes in actue myocardial infarction?
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.
What is fondaparinux? What is its MOA?
Fondaparinux sodium is a synthetic pentasaccharide that inhibits activated factor
X
How long should fondaparinux be given for?
2- 8 days or until discharge (whichever is sooner).
If early angiography is planned, cannot give the patient fondaparinux - what is a suitable antithrombin alternative?
UFH
At what point in fondaparinux CI in renal impairment? What should be used instead?
Should not be used in patients with an eGFR <20ml/min. Use UFH instead.
When should we consider using Tirofiban?
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.
What STAT antiplatelet therapy should be given to a patient with ACS?
300mg Asprin
300mg Clopidogrel - NICE. Local guidelines day 600mg
When might thrombolysis be indicated?
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.
What drugs should be offered to all patients following an acute MI (STEMI/NSTEMI), assuming there are no CI?
ACEi
Dual antiplatelet therapy
Beta blockers
Statin
How should the ACEi be introduced and titrated?
Start at low dose and titrate upwards in short intervals (every 12-24 hours) until max tolerated or target dose is achieved.
What monitoring is required for ACEI?
Base line renal function, U&Es, BP. After each dose increment and then in 1-2 weeks. Then every 3 months.
What is the target bisoprolol dose following ACS?
10mg OD (Start on 2.5mg and titrate up)
What is the target ramipril dose following ACS?
10mg OD (may be in divided doses, 5mg bd)
What is an exercise tolerance test?
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.
What b blocker does NICE advise in ACS?
Atenolol - starting dose 25mg increased to 50mg.
Although a cardioseletive BB like bisoprolol might be preferred as patients are at risk of HF anyway
Patients taking dual antiplatelet therapy may require something for GI protection, what would you advise?
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.
