Ischaemic Heart Disease

Question 1

What are high risk features in angina that would make you consider referring for revascularisation?

Answer 1

Unstable angina at rest
Early post MI angina
Angina unresponsive to medical therapy
Symptoms of CHF
Inability to exercise to stage 2 (6 mins)
Strongly positive ETT at low workload ( >1mm ST depression before completion of stage 2, >2mm at any time)
ST depression persisting for more than 5mins after cessation of exercise
Decline in systolic BP during exercise (>10mmHg)
Development of VT during exercise

Question 2

What is Prinzmetals angina and treatment?

Answer 2

Spasm of coronary arteries
Treat with nitrates and calcium channel blockers
Aspirin can increase severity of attacks

Question 3

Does revascularisation in stable exertional angina affect mortality cf medical treatment?

Answer 3

No

- only reason to revascularise is to improve symptoms

Question 4

What are the types of MI (1-5)?

Answer 4

1. Pathology in coronary artery
2. Increased myocardial oxygen demand or decreased supply
3. Sudden cardiac death
   4a. Related to PCI
   4b. Stent thrombosis
4. Related to CABG

Question 5

What makes up the TIMI risk stratification score for ACS?

Answer 5

Elevated cardiac markers
Age 65 or greater
> 3 CAD risk factors
Prior stenosis of >50%
ST depression >0.5mm
2 or more anginal events in last 24 hours
Aspirin in last 7 days

0-2 low risk
3-4 intermediate
5 or greater high risk

Question 6

What is the action of aspirin?

Answer 6

COX inhibitor therefore inhibits prostaglandin production including thromboxane A2 which causes platelet aggregation

Question 7

What is the action of clopidogrel/praugrel/ticagrelor?

Answer 7

Blocks P2Y12 (an ADP receptor) which stops platelet activation and aggregation

Question 8

What is a concern with clopidogrel use?

Answer 8

That up to 1/3 of patients have low response due to mutations in CYPp450
Also takes longer to work then some of the other ADP blockers

Question 9

What is the mechanism of action of Abciximab and tirofiban?

Answer 9

Inhibit GP IIa/IIIb which is responsible for platelet aggregation

Question 10

What is the early invasive strategy vs conservative strategy in management of ACS?

Answer 10

Take high risk patients to cath lab within 48hours vs medical treatment + refer for angio if rest pain, ST changes recur or evidence of ischaemia on ETT

No difference in outcomes between conservative and early invasive in low risk groups

Question 11

What are drugs used in medical management of stable angina?

Answer 11

Statins
Nitrates - long/short
B-blockers
Calcium channel blockers - dihydropyramidines
Aspirin
- no role for dual anti platelets in stable exertional angina
ACE-I - only if impaired LV fx, diabetic
Nicorandil/perhexiline

Question 12

What benefit is seen with DAPT cf aspirin in ACS?

Answer 12

20 % RR as per CURE trial

But increased bleeding risk

Question 13

What is the morality rate for STEMI in first 30’days?

Answer 13

30%
First 24 hours = arrythmias
After that pump failure

Question 14

How long are bio markers elevated in Ischaemia?

Answer 14

Troponin 7-10 days

CK 48-72 hours, starts to rise within 4-8 hours

Question 15

What is the preferred reperfusion strategy for STEMI

Answer 15

Evidence favors PCI

Question 16

What is the golden hour regarding STEMI?

Answer 16

Symptom of onset and presentation within 1 hour
Needs PCI within 60minutes otherwise fibrinolysis favoured
Time when myocardial salvage is at its highest

Question 17

When would you administer fibrinolysis over PCI?

Answer 17

Presentation to non-PCI capable hospital and time to PCI greater then 120 minutes

Question 18

What is failed fibrinolysis?

Answer 18

Ongoing pain and less the 50 percent reduction in STE in the lead with the greatest elevation
Indication for immediate transfer for rescue PCI as well as shock, HF and intractable arrythmias

Question 19

What is a pharmacoinvasive strategy?

Answer 19

Evidence suggests all patients who receive fibrinolytic should go for planned PCI within 3-24 hours

Question 20

What did the OAT trial show?

Answer 20

No benefit in opening a completely occluded artery 24 hours after presentation if patient is asymptomatic and stable

Question 21

How do you define a successful angioplasty?

Answer 21

Reduction in stenosis to less then 20% diameter of artery

Question 22

What is a stent thrombosis?

Answer 22

Abrupt thrombotic occlusion which presents as MI (30-70%) or sudden death (10-20%)
Longer high risk period in DES due to slow re-epiltheliisation

Question 23

What is stent re-stenosis?

Answer 23

Gradual re-narrowing of scented segment which occurs over 3-12 months and presents with re-current angina
Risk with BMS 10-30%
DES 5-15%
Diabetics are at increased risk

Question 24

Minimum anti platelet therapy in stents

Answer 24

BMS 6 weeks

DES 6 months

Question 25

What are complications of STEMI

Answer 25

LV dysfunction
LV aneurysm
Arrythmias (VT, VF, heart block)
Cardiogenic shock
RV infarction
Recurrent chest pain
Thromboembolism

Question 26

What factors would influence you to put in a BMS

Answer 26

Poor medication adherence
Need for CABG
Anticipated surgery
Long term oral anticoagulation
High bleeding risk

Question 27

What are the ECG findings of each STEMI

Answer 27

Anterior - STE V1-V4
Lateral - I, aVL, V4-V6
Anteroseptal - V1-V3
Inferior - II, III, aVF
Posterior - ST depression V1-V2 with assoc prominent R wave, STE posterior leads
RV infarction - associated inferior (most common) and lateral STE with STE in RV leads

Question 28

What are the ECG findings of LMS occlusion?

Answer 28

Widespread ST depression most common in I, II, V4-V6

STE greater then or equal to 1mm in aVR (STE in aVR greater then V1)