IC6 ACS & AIS Flashcards
What does acute coronary syndrome (ACS) mean?
ACS refers to conditions that suddenly reduces blood flow to the heart.
E.g rupture of atherosclerosis
What does chronic coronary syndrome (CCS) mean?
It refers to conditions that are progressive and asymptomatic, that causes reduced blood flow to the heart.
CCS comprises of stable ischaemic heart disease - e.g angina
(Angina occurs when O2 demand is greater than supply)
E.g of CCS: atherosclerosis
What is the most common trigger of an MI?
Rupture of a plaque.
Atherosclerosis is the main risk factor that leads to MI and stroke
What are the 3 criteria to diagnose a pt w MI?
- Widespread/diffused chest pain
- ST elevation
- High troponin level (20,000 - 30,000)
What is the treatment process when a pt has MI?
- Load aspirin
- 100mg OM in pt with existing aspirin
- 300mg in pt that has never taken aspirin - Load ticagrelor/clopidogrel
- Ticagrelor 180mg
- Clopidogrel 600mg
3a. IV UFH/LMWH
3b. IV bolus GPIIb/IIIa
3c. IV fibrinolytics
3d. IV cangrelor - a type of P2Y12i
The IV agents are used when the clot still continues to persist after Ticagrelor or Clopidogrel
Aspirin, ticagrelor, clopidogrel, IV GPIIb/IIIa, IV Cangrelor are all antiplatelets used for ACS.
What other condition share similar presentation to ACS - e.g MI, angina?
Peptic ulcer disease
The largest and most important blood vessel we must know in the heart is:
The Left Anterior Descending Artery (LAD)
The left main artery splits into 2:
1. Left Anterior Descending (LAD) Artery
2. The circumflex artery
What is in-stent thrombosis?
In-stent thrombosis - is where a thrombus forms in the stent
What is in-stent restenosis?
In-stent restenosis - a gradual re-narrowing of the stented segment over 3 to 12 months
What is the mainstay treatment to prevent in-stent thrombosis?
Dual antiplatelet therapy (DAPT)
What drugs have DDIs with antiplatelets?
- Morphine
- Sildenafil, vardenafil
What is the loading and maintenance dose of:
1. Ticagrelor
2. Clopidogrel
- Ticagrelor
- 180mg [loading dose]
- 90mg BD [maintenance dose] - Clopidogrel
- 600mg [loading dose]
- 75mg daily [maintenance dose]
How long should a pt be on DAPT after initiation?
12 months.
Use DAPT for 12 months in both patient with STEMI & NSTEMI.
After 12months, switch to SAPT - Aspirin 100mg OM for life
If a patient on DAPT were to undergo a surgery, what must we stop and for how long?
DAPT are often:
1. Aspirin + Clopidogrel
2. Aspirin + Ticagrelor
If a patient on DAPT were to undergo surgery, we must stop ticagrelor and clopidogrel for 5 days before surgery.
Aspirin will still continue to be taken.
Which is the preferred DAPT?
1. Aspirin + Clopidogrel
2. Aspirin + Ticagrelor
Aspirin + Ticagrelor
Which is more potent? Clopidogrel or Ticagrelor?
Ticagrelor is more potent than clopidogrel
When do we escalate or de-escalate DAPT?
- If patient is on Clopidogrel DAPT, we can escalate to Ticagrelor DAPT if pt is still ischaemic.
- If patient is on Ticagrelor DAPT, we can
de-escalate to Clopidogrel DAPT if pt is at HBR.
If pt is still at HBR even after de-escalation, we can de-escalate further to SAPT.
What monitoring test should I conduct for follow ups on patients on DAPT?
- FBC
- Check for bleeding
c. Dyspnoea - ticagrelor
Ticagrelor affects adenosine levels, which can then lead to dyspnoea and bradycardia.
HASBLED is a bleeding risk score for patients with AF.
What is the other high bleeding risk score?
The 1 major OR 2 minor criteria high bleeding risk score
(I came up with this name myself :’))
What is in the 1 major OR 2 minor criteria HBR score?
Major:
1. *Anticipated long-term use of OAC
2. *Severe CKD (eGFR <30ml/min)
3. *Hgb < 11g/dL
4. *Active malignancy
5. Spontaneous bleed requiring hospitalization within 6 months
6. Liver cirrhosis w portal HTN
(There are 11 major risk factors, but I’ve only typed down the common ones)
Minor:
1. Age ≥75yo
2. Moderate CKD (eGFR 30-50ml/min)
3. Hgb 11-12.9g/dL men, 11-11.9g/dL women
4. Spontaneous bleeding requiring hospitalization within 12 months
5. Long term use of NSAIDs or steroids
6. Any ischaemic stroke after 6 months
How to determine HBR with 1 major OR 2 minor criteria HBR score?
1 major criterion = 2 minor criteria
As long as pt has 1 major criterion, or 2 minor criteria, he/she has HBR.
Which of the 2 P2Y12i is a prodrug?
Clopidogrel is a prodrug
What enzyme metabolises Clopidogrel into its active form?
CYP2C19
If a patient has loss of function (LoF) gene for CYP2C19, how do we go about managing a patient based on:
- Not at HBR
- High bleeding risk
If pt has LoF for CYP2C19, we should not use clopidogrel as it will be poorly metabolised into its active metabolite.
If patient w LoF for CYP2C19 is not at HBR, we use Ticagrelor.
If patient w LoF for CYP2C19 is at HBR, we consider ticagrelor if bleeding risk is still acceptable.
