IC6: Antithrombotics in AMI and AIS

Question 1

What does FAST stand for

Answer 1

• Face drooping: is the person’s smile uneven
• Arm weakness: can the person raise both arms and keep them up
• Speech difficulty: does the person’s speech sound slurred or unclear
• Time to call 995: the clot can be thrombolysed within 3-4.5h

Question 2

What should be done for AIS patients who can be started on rtPA?

Answer 2

start r-TPA asap and start SAPT (aspirin) after 24h and within 48h and then evaluate the stroke mechanism

Question 3

What should be done for AIS patients who cannot be started on rtPA?

Answer 3

if minor stroke risk start DAPT for 21d asap;

if not minor stroke risk, start SAPT asap

Question 4

What should be done if the stroke is cardioembolic in nature?

Answer 4

stop the antiplatelet and look for underlying cardio sources (eg. in underlying AF, start OAC like apixaban or rivaroxaban)

Question 5

What should be done if the stroke is non-cardioembolic in nature?

Answer 5

assess if the patient has severe major ICAS (intracranial arterial stenosis)

• If there is no severe major ICAS, proceed with lifelong SAPT
• If there is severe major ICAS, proceed with lifelong SAPT and consider adding clopidogrel for 90 days

Question 6

How is aspirin dosed?

Answer 6

300mg Loading dose
100mg OM lifelong

Question 7

How is clopidogrel dosed?

Answer 7

300/600mg Loading dose
75mg OM

Question 8

How is ticagrelor dosed?

Answer 8

180mg Loading dose
90mg BD up to 12m
60mg BD extended therapy

Question 9

What are the remarkable side effects of ticagrelor?

Answer 9

paroxysmal dyspnea and bradycardia (due to adenosine effects)

Question 10

When should clopidogrel and ticagrelor be used?

Answer 10

Clopidogrel for stroke
Ticagrelor for MI and ACS

Question 11

Compare time to platelet aggregation between ticagrelor and clopidogrel

Answer 11

ticagrelor has a faster time to platelet aggregation (and therefore faster recovery from platelet activity)

Question 12

What is the PRECISE-DAPT score used for?

Answer 12

Assess bleeding risk for patients with drug-eluting stents to consider when to discontinue anticoagulants

PRECISE-DAPT score > 25 = high bleeding risk

Question 13

What are the concerns when using DES?

Answer 13

Usually give immunosuppressants together, which are non-selective and therefore affect healing throughout the body (risk for falls and cuts that cannot heal properly, hence must consider antiplatelet duration)

Cover for at least 12m, or 3-6m if patient at high bleeding risk

Question 14

What are the major risk factors for PRECISE-DAPT? (7)

Answer 14

• Anticipated risk of long-term OAC
• Severe or end-stage CKD
• Hb < 11 g/dL
• Spontaneous bleeding
• Thrombocytopenia
• Liver cirrhosis
• Active malignancy and recent major surgery or trauma within 30 days before PCI

Question 15

What are the CV risk factors related to AMI and AIS? (7)

Answer 15

• Cholesterol → assess ASCVD risk, personalise with risk enhancers and reclassify wth CAC as needed
• High BP → maintain BP below 130/80 mmHg
• Physical activity → perform at least ≥ 150min a week of moderate activity or ≥ 75 min a week of vigorous physical activity
• Aspirin use → low-dose aspirin for primary prevention is now reserved for select high-risk patients
• T2DM → control through diet and exercie
• Diet → emphasis on intake of vegetables, fruits, nuts, legumes, fish and wholw grains
• Tobacco → pharmacotherapy and behavioural recommendations to maximise quit rates

Question 16

Which are the wild types, LoF and GoF types for CYP2C19?

Answer 16

*1 = “wild type”
*2 and *3 = “loss-of-function”
*17 = “gain-of-function”

Question 17

When should LoF genes be considered in choosing antiplatelet therapy?

Answer 17

As long as the patient has either *2 or *3 in one of their allele pairs, they are considered at least intermediate metabolisers or poor metabolisers

Consider ticagrelor over clopidogrel in these patients