Acute Coronary Syndrome

Question 1

Describe the spectrum ACS? (4 points )

Answer 1

• Unstable angina
• Non-ST elevation myocardial infarction
• ST-elevation myocardial infarction
• Sudden cardiac death

Question 2

Common pathogenesis of ACS?

Answer 2

• Atherosclerotic plaque rupture or erosion
• Superimposed platelet aggregation and thrombosis
• Vasospasm, and vasoconstriction

Question 3

What are the two goals of pharmacotherapy?

Answer 3

• Increase myocardial oxygen supply

- Decrease myocardial oxygen demand

Question 4

How do you increase myocardial oxygen supply?

Answer 4

-Through coronary vasodilation

Question 5

How do you decrease myocardial oxygen demand?

Answer 5

• Decrease in heart rate
• Decrease blood pressure
• Decrease preload or myocardial contracility

Question 6

What do patients with STEMI have a high likelihood of?

Answer 6

A Coronary thrombus occulding the infarct artery

Question 7

How does STEMI usually occur?

Answer 7

Coronary artery occlusion due to formation of thrombus overlying an atheromatous plaque

Question 8

What thrombolytic agents are available today?

Answer 8

Serine proteases

Question 9

How do thrombolytic agents work?

Answer 9

converting plasminogen to the natural fibrinolytic agent plasmin

Question 10

What does plasmin act on?

Answer 10

fibrinogen

Question 11

What are the two categories of thrombolytic agents?

Answer 11

1. Fibrin-specific agents

2. Non-fibrin specific agents

Question 12

name 3 fibrin specific agents?

Answer 12

• Alteplase
• Reteplase
• Tenecteplase

Question 13

How to fibrin specific drugs work?

Answer 13

All catalyse conversion of plasminogen to plasmin in the absence of fibrin

Question 14

Where are streptokinases taken from?

Answer 14

from mycobacterium (causes sensitation so only one dose available)

Question 15

When would you not give thrombolytic drugs? (7)

Answer 15

• Prior intracranial hemorrhage
• Known structural cerebral vascular lesion
• Known malignant intracranial neoplasm
• Ischaemic stroke within 3 months
• Suspected aortic dissection
• Active bleeding/diathesis
• Significant closed-head trauma or facial trauma within 3 months

Question 16

What do you do if there is no evidence of a STEMI ACS?

Answer 16

• Aspirin
• Tigagrelor/clopidogrel-antiplatlete
• Fondaparinux/LMW heparin
• IV nitrate
• Analgesia
• Beta Blockers

Question 17

What is the dose given of aspirin?

Answer 17

low ( 75-100mg)

Question 18

What is aspirin is apotent inhibitor of what?

Answer 18

Platelet thromboxane A2 production

Question 19

what can the daily use of aspirin reduce the risk of?

Answer 19

ACute MI (mortality 23%)
Unstable angina (death 50%)
Secondary prevention (reduce reinfarction by 32% and combines vascular events by 25%)

Question 20

What is clopidogrel?

Answer 20

a Pro-drug

Question 21

How does clopidogrel work?

Answer 21

Inhibits ADP receptor activated platelet aggregation

Question 22

What receptor does clopidogrel act on?

Answer 22

P2Y12 ADP

Question 23

What is P2Y12 ADP responsible for?

Answer 23

Important in aggregation of platelets and cross linking by fibrin

Question 24

What is Clopidogrel activated by?

Answer 24

CYP2C19

Question 25

How much of the population have low levels of CYP2c19?

Answer 25

14%

Question 26

What is the IIb/IIIa complex?

Answer 26

it is a receptor fibrinogen, fibronectin and von WF

Question 27

What happens when IIb/IIIa complex is activated?

Answer 27

"final common pathway" for platelet aggregation and cross-linking of platelets by fibrin

Question 28

What is clopidrogrel always used in combination?

Answer 28

aspirin

Question 29

What is more effective than clopidogrel with aspirin?

Answer 29

Ticagrelor and aspirin

Question 30

What is more rapid and consistent in than clopidogrel in inhibiting the ADP- platelet aggregation

Answer 30

Prasugrel

Question 31

What are clopdiogrel and prasugrel members of?

Answer 31

Thienopyridine class of ADP receptor inhibitors

Question 32

Name the four low molecular weight heparin?

Answer 32

- Enoxaparin - Dalteparin - Tinzeparin - Fondaparinux

Question 33

What is the most safe in terms of major bleeds of the low molecular weight heparin?

Answer 33

Fondaparinux

Question 34

Why is fondaparinux a good choice?

Answer 34

- Single chemical entity - Synthetic pentasaccaride - Highly selective for antithrombin - Once-daily administration - No need for platelet monitoring

Question 35

What are beta blockers used for?

Answer 35

- In treatment of cute MI | - For secondary prevention in the survivors of an acute MI

Question 36

How do beta blockers work?

Answer 36

Competitvely inhibit the myocardial effects of circulating catecholamines and reduce myocardial oxygen comsumption by lowering heart rate, blood pressure and myocardial contractility.

Question 37

How much does atenolol or metoprolol reduce mortality by?

Answer 37

10-15%