Acute Coronary Syndrome Therapy

Question 1

Common causes of ACS (4)

Answer 1

• Atherosclerotic plaque rupture or erosion
• Superimposed platelet aggregation and thrombosis
• Vasospasm and vasoconstriction
• Subtotal or transient total occlusion of vessel

Question 2

What ACS patient has a high lilelihood of coronary thrombus occluding the infarct artery

Answer 2

STEMI patient

Question 3

if no PCI has been performed within 2 hours what should be used

Answer 3

Thrombolysis

Question 4

What type of agents are thrombolytic drugs

Answer 4

Serine proteases

Question 5

What do thrombolytic agents do

Answer 5

Converts plasminogen to activated state Plasmin

This lyses clots by breaking down fibrin and fibrinogen

Question 6

What are the 2 types of Thrombolytic agents

Answer 6

Fibrin specific

Non-fibrin specific

Question 7

Fibrin specific agenst

Answer 7

Alteplase
Reteplase
Tenecteplase
Catalyse conversion of plasminogen to plasmin

Question 8

Non-fibrin specific agents

Answer 8

Streptokinase

Catalyse systemic fibrinolysis

Question 9

Contraindication of using thrombolysis (7)

Answer 9

Risk of heavy bleeding:
• Prior intracranial haemorrhage
• Known structural cerebral vascular lesion
• Known malignant intracranial neoplasm
• Ischaemic stroke within 3 months
• Suspected aortic dissection
• Active bleeding or bleeding diathesis (excluding menses)
• Significant closed-head trauma or facial trauma within 3 months

Question 10

If there is no evidence of STEMI what medication should be used (6)

Answer 10

• Aspirin
• Tigagrelor/Clopidogrel (anti-platelet/blood thinner)
• Fondaparinux/LMW (low molecular weight) heparin (anti-coagulant agents)
• Intravenous nitrate
• Analgesia
• Beta Blockers

Question 11

What other medications can be used

Answer 11

Prasugrel
Giibiia inhibitors
Statins

Question 12

Management to reduce risk from NSTEMI

Answer 12

• PCI or CABG
• Aspirin- potent inhibitor of thromboxane A2 production which stimulates aggregation and vasoconstriction
• Clopidogrel, prasugrel, ticagrelor, ticlopidine or cilostazol
• Heparin (LM)
• Fondaparinux
• Giib/iiia receptor blockers
• Statins
• B blockers

Question 13

What is the mechanism of aspirin

Answer 13

Inhibits the production of thromboxane A2 which stimulates aggregation and vasoconstriction

Question 14

When can aspirin be used daily (3)

Answer 14

Acute MI
Unstable angina
Secondary prevention

Question 15

What is the mechanism of clopidogrel

Answer 15

Anti-platelet
Prodrug
Inhibits ADP receptor activated platelet aggregation of platelets and crosslinking of fibrin

Question 16

What receptor does Clopidogrel specifically inhibit

Answer 16

P2Y12 ADP which blocks the activation of the GP iib/iiia pathway

Question 17

What is the iib/iiia complex a receptor for

Answer 17

Fibrinogen
Fibronectin
Vin WF

Question 18

What must clopidogrel be always used with

Answer 18

Aspirin

Question 19

Why might someone have clopidogrel resistance

Answer 19

This drug is activated by CYP2C19 and 14% of the population have low levels of this enzyme

Question 20

What are the benefits of using Prasugrel over clopidogrel

Answer 20

Inhibits ADP-induced platelet aggregation more rapidly, more consistently

Question 21

Low molecular weight heparin 94)

Answer 21

• Enoxaparin
• Dalteparin
• Tinzeparin
• Fondaparinux

Question 22

What is GIIb/IIIa

Answer 22

Integrin complex found on platelets

Question 23

What is the role of GPIIb/IIIa

Answer 23

induces production of fibrinogen once activated by ADP and undergoes a conformational change

Question 24

What is the action of GPIIb/IIIa inhibitors

Answer 24

inhibits fibrinogen binding to the activated form of GPIIb/IIIa on tow adjacent platelets and blocking aggregation

Question 25

Anticoagulant drugs target

Answer 25

Factor Xa

Production of thrombin from prothrombin

Question 26

Antiplatelet drugs

Answer 26

• Inhibit ADP activation of GPIIb/IIIa pathway (aspirin, clopidogrel, prasugrel)
• Inhibition of ADP leads to an Inhibition of the activation of thromboxane

Question 27

When can beta blockers be used

Answer 27

Post MI

Secondary prevention

Question 28

Examples of B blockers

Answer 28

IV atenolol

IV metoprolol

Question 29

Mechanism of beta blockers

Answer 29

Competitively inhibit the myocardial effects of catecholamines and reduce oxygen consumption by reducing HR, BP and contractility

Question 30

Who would receive a beta blocker within 24 hours of admission

Answer 30

> 70 years
HR >110 bpm
Systolic pressure <120 mmHG