Haematology - ACS/CCS/AIS/TIA

Question 1

If ACS suspected, what is the regimen?

Answer 1

1. On the ambulance if ACS suspected, load aspirin 100mg/300mg (if aspirin naive).
2. Confirm AMI Dx
3. Load P2Y12i pre PCI (Tica>Clopi)
4. Angioplasty = PCI
   - For imaging, for reperfusion w stent
   - IV bolus UFH/LMWH or
   - IV bolus GpIIb/IIIa inhib f/b infusion w IV Cangrelor (P2Y12i)
   - RARELY fibrinolytic - rTPA

Question 2

What is the indication for DAPT?

Answer 2

Insertion of a stent which is thrombogenic, can form clots. So we need to put patient on double antiplatelet therapy to prevent the clot from forming. As the risk of clot formation decreases with time, after 12months (ACS) we can stop one antiplatelet and continue on the other antiplatelet lifelong (aspirin)

Question 3

Why do we have drug eluting stents?

Answer 3

There is instent restenosis where the plaque narrow the vasculature lumen. Drug eluting stents are proposed to counteract this risk

Question 4

What are the principles for the recommended regimens for ACS?

Answer 4

For the general population:
DAPT w Tica>Clopi

For pts unable to receive Tica or Prasu:
DAPT w Clopi

For STEMI pt receivg thrombolysis:
DAPT w Clopi

Question 5

What is the dosing for Clopidogrel in ACS and CCS?

Answer 5

LD: 300 mg
Maintenance: 75 mg once daily

Question 6

How do we determine the duration of therapy for ACS?

Answer 6

Default for ACS: 12mo

Determine if pt is at high bleeding risk. Determine pt’s ischemic risk (CHA2DS2-VASc, risk of ACS event).
Bleeding risk takes precedence over ischemic risk.

If pt has HBR - Min 2 minor criteria or 1 major criteria, shorten DAPT to 3mo.

Extend DAPT if pt has recurrent ischemic events and no high bleeding risk.

Question 7

What are the HBR criteria?

Answer 7

Major
- Anticipated use of long term OACs
- Severe or end stage CKD - eGFR< 30mL
- Hb < 11g/dL
- Mod-severe baseline thrombocytopenia (platelet count < 100 x10^9/L)
- Spont bleeding req hospitalisation or transfusion in past 6mo or any time if recurrent
- HTN (SBP > 160 mm Hg)
- Chronic bleeding diathesis

Minor
- Mod CKD - eGFR 30-59mL/min
- Hb < 11-12.9g/dL (M), <11-11.9g/dL (F)
- Spont bleeding req hospitalisation or transfusion in past 12mo (& NOT meeting major criteria)
- Liver cirrhosis
- Active malignancy
- Hx of severe ischemic stroke (recent 6mo)
- Any ischemic stroke at any time, not meeting major criteria
- Age>=75y.o.
- Recent major surgery or major trauma (30d before PCI)
- Long term NSAID or steroid use

Question 8

What are the concerns w Clopidogrel that need to be observed for ACS?

Answer 8

Loss of fn mutation of CYP2C19 w (*2 & *3 alleles) –> poor metabolisers –> increased clopidogrel. Increased risk of MACE. Relative risk of ischemic events decreased w tica/prasu in this grp.

Question 9

If triple anticoag therapy is required what do we do?

Answer 9

Rivaroxaban may be considered (only one studied in ACS) but not well practised due to bleeding risk

Question 10

What is the recommended regimen w CCS (General stable CAD, SIHD)?

Answer 10

1. Pretreatment w clopidogrel if probability of PCI is high
2. Post PCI:
   DAPT w Clopi>Tica

Question 11

What is the duration of therapy in CCS?

Answer 11

6mo

Question 12

How do we proceed for pts on DAPT scheduled for non-cardiac surgery?

Answer 12

Consider risk assoc w disrupting DAPT or continuing aspirin alone vs delaying surgery till completion of 6mo DAPT post MI.

Only disrupt when discussed w cardiologist: risk of bleeding vs ischemic event

Question 13

What are the recommended agents for ACS and CCS?

Answer 13

Antiplatelets: Aspirin, Clopidogrel, Ticagrelor, Prasugrel

Question 14

Do anticoagulants have a place in ACS/CCS therapy?

Answer 14

NO