Acute Coronary Disease Therapy

Question 1

What is the goal of treating ACS?

Answer 1

Increase 02 supply to the heart through:
- coronary vasodilation
Decrease oxygen demand from the heart by:
- decreasing HR
- decreasing blood pressure
- decreasing preload or myocardial contract ability

Question 2

Describe the type of thrombosis therapy that is given and how it works.

Answer 2

Fibrinolytics:
Serine proteases that work by converting plasminogen to the natural fibrinolytic agent plasmin
Plasmin lyses clots by breaking down the fibrinogen and fibrin contained in the clot.

Question 3

What are the 2 categories of fibrinolytic categories?

Answer 3

1. Fibrin specific agents (all catalyst conversion of plasminogen to plasmin in the absence of fibrin.
2. Non fibrin specific agents, such as streptokinase, catalyse systemic fibrinolysis

Question 4

What are the contraindication of fibrinolytics? (Thrombolysis therapy)

Answer 4

Previous intra-cranial haemorrhage
Active bleeding or bleeding diathesis
Significant closed head trauma or facial trauma within 3 months
Known structural cerebral vascular lesion
Known malignant intracranial neoplasm
Ischemic stroke within 3 months
Suspected aortic dissection

Question 5

What is the medical treatment if there is no evidence of STEMI?

Answer 5

Aspirin
Tigagrelor/ Clopidogrel
Fondaparinux (LMW heparin)
IV nitrate
Analgesia
Beta blockers

Question 6

Why is aspirin used?

Answer 6

Aspirin is a potent inhibitor of platelet thromboxane A2 production
Thromboxane stimulates platelet aggregation and vasoconstriction

Question 7

Why is beta blockers used?

Answer 7

Reduces the heart rate so the 02 demand decreases

Question 8

What management is given to reduce risk of NSTEMI?

Answer 8

PCI or CABG
Aspirin
Clopidogrel, prasugrel, ticagrelor, ticlopidine, or cilostazol
Heparin
Fondaparinux
Statins
Beta blockers
GIIb/IIIa receptor blockers

Question 9

Describe how clopidogrel works.

Answer 9

Clopidogrel is a prodrug
It irreversibly inhibits P2Y12 ADP receptor which is important in aggregation of platelets and cross linking by fibrin
It does this by blocking the activation of the GP IIb,IIIa pathway which is the final common pathway for platelet aggregation and cross linking of platelets by fibrin

Question 10

Because clopidogrel is a prodrug, what activates it?

Answer 10

Cyp 2C19

Question 11

What is the difference between clopidogrel and prasugrel?

Answer 11

Prasugrel inhibits ADP- induced platelet aggregation more rapidly more consistently
But the bleeding rate from prasugrel is higher

Question 12

Name a drug which is a low molecular weight heparin.

Answer 12

Fondaparinux

Question 13

Fondaparinux is a selective inhibitor of what?

Answer 13

Factor Xa

Question 14

How does IV GPIIa/IIIa inhibitors work?

Answer 14

They block platelet aggregation by inhibiting fibrinogen binding to a conformationally activated form of GPIIb/IIa receptor on two adjacent platelets.
(Activated GPIIb/IIa aids in platelet aggregation as its the receptor for fibrinogen)

Question 15

When should you avoid using beta blockers?

Answer 15

When the patient is at risk of cardiogenic shock, symptoms possibly related to coronary vasospasm or is on coccaine