Antiplatelet, Antithrombotic, and Thrombolytic Agents

Question 1

What is protamine currently synthesized from?

Answer 1

Biotechnology

Protamine was originally produced from fish products.

Question 2

Who should avoid protamine?

Answer 2

Patients with a strong fish allergy and those taking NPH insulin

Due to increased risk of a histamine-mediated reaction.

Question 3

What is the effect of high doses of protamine?

Answer 3

Can act as an anticoagulant

For usual doses, this effect is weak.

Question 4

What do prasugrel and clopidogrel require for activation?

Answer 4

Hepatic cytochromes

Both drugs require oxidation to generate their active drug metabolite.

Question 5

How many oxidative steps does prasugrel require for activation?

Answer 5

One oxidative step involving CYP2C19

Question 6

How many oxidative steps does clopidogrel require for activation?

Answer 6

Two oxidative steps

Question 7

What is a primary contraindication for thrombolytic therapy?

Answer 7

Lifethreatening bleeding such as intracranial hemorrhage

Question 8

Is a history of ischemic stroke a contraindication for thrombolysis in STEMI?

Answer 8

No, unless the stroke occurred in the last 3 months

Question 9

What is one major risk associated with premature discontinuation of antiplatelet therapy?

Answer 9

Increased risk for stent thrombosis

Hazard ratio of 90 for stent thrombosis was found in one large-scale registry.

Question 10

What is the recommended duration of dual antiplatelet therapy (DAPT) after first-generation DES?

Answer 10

12 months

Question 11

What is bivalirudin characterized as?

Answer 11

A short amino acid sequence with the shortest half-life among IV direct thrombin inhibitors

Question 12

What is a notable characteristic of cangrelor in relation to clopidogrel?

Answer 12

Reduces the odds of MACE by 19% with no difference in GUSTO severe bleeding

Question 13

What are some factors released from platelets?

Answer 13

ADP, fibrinogen, sCD40L

These factors either accelerate coagulation or promote inflammation.

Question 14

What distinguishes ticagrelor from other oral antiplatelet agents?

Answer 14

It is the first orally available P2Y12 receptor antagonist that reversibly affects the receptor

Question 15

What is the risk of major bleeding for a non-ACS catheterization and possible PCI?

Answer 15

<1%

Question 16

Which access method has shown lower rates of major bleeding?

Answer 16

Radial access compared to femoral access

Question 17

What has contributed to the decrease in major bleeding rates in recent years?

Answer 17

Changes in practice despite the use of multiple antiplatelets and anticoagulants

Question 18

What factors are important when assessing anticoagulation with enoxaparin?

Answer 18

Dose given, hours since dose, renal function

Creatinine clearance influences the anticoagulant effect.

Question 19

What is the mechanism of heparin-induced thrombocytopenia (HIT)?

Answer 19

Antibody generation in response to a heparin–platelet factor complex

Question 20

What is the main activity of thrombin?

Answer 20

Facilitating the conversion of fibrinogen to fibrin

Question 21

What role does argatroban play in anticoagulation?

Answer 21

Hepatically metabolized

Question 22

What is the primary risk associated with NSTEMI-ACS patients receiving fibrinolytic therapy?

Answer 22

Higher rate of MI

Question 23

What is cangrelor’s classification?

Answer 23

Modified ATP derivative, irreversibly inhibits the ADP receptor of platelets

Question 24

What is the effect of abciximab on platelet receptors?

Answer 24

Avidly binds to platelet receptors

Question 25

What is the significance of the TRITON trial results?

Answer 25

Prasugrel decreased composite ischemic endpoint but increased major bleeding rate

Question 26

What is the effect of idarucizumab and andexanet?

Answer 26

Effectively reverse the effects of anti-IIa and anti-Xa oral agents

Question 27

What is a notable characteristic of eptifibatide?

Answer 27

Given in excess of platelet receptors, making platelet transfusions ineffective

Question 28

What does the DANISH Health System track?

Answer 28

Prescriptions and hospitalizations related to bleeding

Question 29

What is the effect of adexanet and protamine on LMWHs?

Answer 29

They will partially reverse the effects of LMWHs

Adexanet is used for reversing the effects of certain anticoagulants, while protamine is primarily used for reversing heparin.

Question 30

Why are platelet transfusions not helpful for eptifibatide?

Answer 30

Eptifibatide is given in a several hundred-fold excess of platelet receptors due to its pharmacokinetics and pharmacodynamics

This means that the drug binds to the receptors extensively, rendering transfusions ineffective.

Question 31

What hazard ratio was observed for bleeding-related hospitalizations among those receiving triple therapy in the DANISH Health System?

Answer 31

1.41

This indicates a significant increase in the risk of bleeding-related hospitalizations.

Question 32

What was the percentage increase in BARC ≥ 2 bleeding from the ISAR TRIPLE trial when comparing 6 weeks vs. 6 months of clopidogrel?

Answer 32

From 7.6% to 12.2%

This represents approximately a 60% increase in bleeding events with the extended duration.

Question 33

In the WOEST trial, what was the bleeding occurrence rate at 1-year follow-up for the triple therapy group?

Answer 33

44.4%

Compared to 19.4% for the double therapy group, indicating more than twice as often bleeding in the triple therapy group.

Question 34

What did the DAPT study show regarding major adverse cardiac and cerebrovascular events (MACCE) with prolonged antiplatelet therapy?

Answer 34

Reduced from 9% to 4.3% (p < 0.001)

This demonstrates the antithrombotic benefit of prolonged therapy.

Question 35

What was the increase in GUSTO moderate or severe bleeding with prolonged DAPT?

Answer 35

From 1.6% to 2.5% (p = 0.001)

This highlights the trade-off between benefits and risks in prolonged antiplatelet therapy.

Question 36

What is the recommended therapy for patients at high risk of postprocedure bleeding with oral anticoagulation?

Answer 36

Perioperative UFH therapy

This is particularly for patients with mechanical valves or recent thrombosis.

Question 37

What should be done if a patient’s INR remains elevated after discontinuing warfarin?

Answer 37

Consider using a particularly small arterial sheath (5-Fr) in the radial artery

This is to manage the risk of bleeding during procedures.

Question 38

Fill in the blank: The occurrence of stent thrombosis and MI was increased in the first ______ months after stopping clopidogrel.

Answer 38

3

This emphasizes the critical period post-antiplatelet therapy.

Question 39

True or False: The patient’s stent placement was done recently, raising concerns for stent thrombosis.

Answer 39

False

The stent placement was done many years before, alleviating concerns.