Unstable Angina

Question 1

Acute coronary syndrome (ACS) is usually the result of a thrombus from an atherosclerotic plaque blocking a coronary artery. When a thrombus forms in a fast-flowing artery, it is formed mainly of platelets. This is why antiplatelet medications such as aspirin, clopidogrel and ticagrelor are the mainstay of treatment.

There are three types of acute coronary syndrome:

Unstable angina
ST-elevation myocardial infarction (STEMI)
Non-ST-elevation myocardial infarction (NSTEMI)

Question 2

Unstable angina (UA) is due to transient myocardial ischaemia (MI), often resulting from atherosclerotic plaque rupture and subsequent thrombus formation in the coronary arteries. The symptoms are due to a mismatch in myocardium oxygen demand and supply. Which of the following is NOT a risk factor for UA?

1 - Age
2 - Gender
3 - Tobacco use
4 - Dyslipidaemia and Hypertension
5 - Diabetes mellitus
6 - Obesity and Sedentary lifestyle
7 - Family history

Answer 2

2 - Gender

Question 3

Although there are a variety of causes leading to unstable angina, which of the following can also cause UA?

1 - Atherosclerotic plaque disruption
2 - Vasospasm
3 - Cocaine use
4 - All of the above

Answer 3

4 - All of the above

• Atherosclerotic plaque disruption = most common cause, may be due to transient or partial occlusion of the coronary artery.
• Vasospasm = UA episodes without significant atherosclerosis (Prinzmetal’s angina).
• Cocaine use: Cocaine can induce coronary vasospasm leading to unstable angina. It also accelerates atherosclerosis and increases platelet aggregation.

Question 4

Coronary atherosclerosis is a complex inflammatory process. Although the exact cause is unknown, the trigger id commonly linked with damage and/or dysfunction to the epithelium of blood vessels. Which of the following has not been identified as a trigger causing epithelium damage and/or dysfunction?

1 - morbid hypertension
2 - biochemical abnormalities (LDL)
3 - diabetes mellitus
4 -immunological factors (free radicals from smoking)
5 - inflammation
6 - genetic alteration
7 - biochemical abnormalities (HDL)

Answer 4

7 - biochemical abnormalities (HDL)

Question 5

What is the earliest stage of atherogenosis (atherosclerotic plaque formation, leading to coronary artery heart disease)?

1 - fatty streaks
2 - LDL infiltration
3 - cytokine release
4 - foam cells build up

Answer 5

1 - fatty streaks

Question 6

Following the initial damage/dysfunction to blood vessel epithelium, what is the first things that occurs leading to coronary atherosclerosis?

1 - increased cytokine expression
2 - foam cells build up
3 - LDL cross epithelium
4 - macrophages phagocytose LDL through oxidation

Answer 6

3 - LDL cross epithelium

Question 7

Following the initial damage/dysfunction to blood vessel epithelium, LDL cross the epithelium. What then occurs leading to coronary atherosclerosis?

1 - increased cytokine expression
2 - foam cells build up
3 - LDL cross epithelium
4 - macrophages phagocytose LDL through oxidation

Answer 7

4 - macrophages phagocytose LDL through oxidation

• macrophages cross endothelium to get to LDLs

Question 8

Following the initial damage/dysfunction to blood vessel epithelium, we have dead macrophages full of LDLs, called foam cells. What is the next thing that occurs leading to coronary atherosclerosis?

1 - increased cytokine expression
2 - foam cells build up
3 - LDL cross epithelium
4 - macrophages phagocytose LDL through oxidation

Answer 8

2 - foam cells build up

• foam cells are macrophages that have died and begin secreting cytokines
• attract more monocytes to area

Question 9

What is a fatty streak, which is a term used in atherosclerosis?

1 - build up of HDL beneath epithelium
2 - build up of LDL beneath epithelium
3 - build up of foam cells beneath epithelium
4 - build up of macrophages beneath epithelium

Answer 9

3 - build up of foam cells beneath epithelium

Question 10

Fatty streaks can occur in any patients throughout their life. Why are fatty streaks dangerous?

1 - thrombogenic
2 - increase blood pressure
3 - increase cytokine release
4 - decrease HDL levels

Answer 10

1 - thrombogenic

• susceptible to blood clotting on it

Question 11

Fatty streaks formed by dead macrophages containing LDL are thrombogenic, meaning they are susceptible to blood clotting. This causes the release of platelet derived growth factor, and then smooth muscle migration and proliferation to the tunica intima from the tunica media. Smooth muscle cells then secretes things that become the fibrous cap. Which of the following is NOT a component of the fibrous cap?

1 - collagen
2 - elastin fibrous cells
3 - elastic cartilage
4 - proteoglycans

Answer 11

3 - elastic cartilage

• purpose of the fibrous cap is to prevent blood clotting

Question 12

Together the fibrous cap and fatty streak are called what?

1 - thrombosis
2 - embolus
3 - atheroma
4 - plaque

Answer 12

4 - plaque

Question 13

In addition to secreting the contents that make up the fibrous cap, what else do smooth muscle cells secrete in the fatty streak?

1 - Ca2+
2 - Na+
3 - Mg+
4 - Cl-

Answer 13

1 - Ca2+

• normally deposited into vessel walls by LDL
• cholesterol crystals are also present

Question 14

In addition to secreting the contents that make up the fibrous cap, smooth muscle cells secrete Ca2+ into the fatty streak, which is normally deposited into the vessel walls by LDL. Normally what then removes the Ca2+ to stop the hardening of blood vessel walls?

1 - lipoprotein lipase
2 - HDL
3 - VLDL
4 - albumin

Answer 14

2 - HDL

• plaques impair HDLs ability to remove Ca2+

Question 15

Once Ca2+ has been deposited into the fatty streak and vessel walls, do the vessel walls become more elastic or stiff?

Answer 15

• stiff due to Ca2+ forming crystals

Question 16

What generally causes a myocardial infarction that has been in the arteries for some time?

1 - low nitrates
2 - increased Na+ and K+
3 - fibrous cap of plaque becomes unstable and ruptures
4 - endothelium become damaged and leak collagen

Answer 16

3 - fibrous cap of plaque becomes unstable and ruptures

• rupture is due to thinning of the cap and core expansion
• thrombogenic contents (foam cells) of plaque leak out causing blood clot

Question 17

During the rupture of fibrous cap or the expansion of a plaque, what % of blood vessel occlusion can lead to stenosis and lead to ischaemia given any increase in O2 demand?

1 - 10%
2 - 30%
3 - 50%
4 - 70%

Answer 17

3 - 50%

• 50% reduction in luminal diameter causes a 70% reduction in luminal cross-sectional area

Question 18

What is the earliest stage of atherogenosis (atherosclerotic plaque formation, leading to coronary artery heart disease)?

1 - fatty streaks
2 - LDL infiltration
3 - cytokine release
4 - foam cells build up

Answer 18

1 - fatty streaks

Question 19

As fatty streaks form in the endothelium, platelets bind to damaged epithelium. They then release platelet derived growth factor that drives the development of what?

1 - more macrophages migrate to the area
2 - lymphocytes are activated
3 - smooth muscle cell proliferation
4 - increased cytokine secretion from fatty streak

Answer 19

3 - smooth muscle cell proliferation

• smooth muscle cells move from tunica media to tunica intima

Question 20

When plaques rupture, what is the primary content that is very atherogenic that leaks out causing the formation of red thrombus?

1 - collagen
2 - Ca2+
3 - foam cells
4 - smooth muscle cells

Answer 20

3 - foam cells

• thrombus is blood clot
• embolism is clot moving in blood

Question 21

Once a plaque ruptures a red thrombus is formed. This thrombus may cause the following:

• occlusion of the artery
• partial occlusion of the artery
• embolise distally
• plaque progression

Match the above with the following: ST elevated MI, Non-ST elevation MI, stable angina and unstable angina:

Answer 21

• ST elevated MI = occlusion of the artery
• Non-ST elevation MI = partial occlusion of the artery
• stable angina = embolise distally
• unstable angina = plaque progression

Question 22

Does unstable angina present with symptoms during times of exertion?

Answer 22

• No

It may, but typically symptoms present at rest or low intensity.

Unpredictable, and hence the name unstable

Question 23

Unstable angina can be classified based on its severity. Which of the following is the most severe?

1 - New-onset severe angina
2 - Increasing or crescendo angina
3 - Rest or nocturnal angina

Answer 23

3 - Rest or nocturnal angina

May be a sign of critical myocardial ischemia.

Question 24

The stereotypical presentation of unstable angina (UA) often involves a patient experiencing chest discomfort at rest or minimal exertion. How long does this typically last?

1 - <30 seconds
2 - <5 minutes
3 - <20 minutes
4 - <1 hour

Answer 24

3 - <20 minutes

Question 25

The stereotypical presentation of unstable angina (UA) often involves a patient experiencing chest discomfort at rest or minimal exertion. Which of the following matches the typical description of UA? 1 - pressure across the chest 2 - heaviness and/or tightness in the chest 3 - radiating pain to the neck, jaw, shoulder, back or arm 4 - all of the above

Answer 25

4 - all of the above

Question 26

In addition to the typical features of unstable angina (UA), all of the following can occur, but which is very unlikely? 1 - dyspnoea 2 - pitting oedema 3 - nausea and vomiting 4 - syncope 5 - sweating

Answer 26

2 - pitting oedema Common in heart failure, but not UA

Question 27

When examining a patient with unstable angina (UA), the patient may appear normal. But which of the following may be found in a patient with active unstable angina during the time of the examination? 1 - fourth heart sound (S4) 2 - hypotension 3 - transient mitral regurgitation due to papillary muscle dysfunction 4 - pallor and cool extremeties 5 - all of the above

Answer 27

5 - all of the above Atypical symptoms, especially in the elderly may include: - epigastric pain - indigestion-like symptoms - isolated diaphoresis (excessive sweating)

Question 28

Which 2 of the following are the 1st line investigations in a patient with suspected unstable angina (UA)? 1 - echocardiogram 2 - troponin 3 - ECG 4 - creatine kinase MB 5 - chest X-ray

Answer 28

2 - troponin Measured immediately and 3h from symptom onset. An increase indicates myocardial damage, but doesn't distinguish between MI and UA 3 - ECG Echocardiogram gives information about the left ventricle, wall anomalies or other pathology Chest X-ray to rule out other differentials

Question 29

Is troponin typically raised in unstable angina (UA)?

Answer 29

- no This is how to distinguish between UA and STEMI or NSTEMI. Gastroesophageal Reflux Disease - UA = relief with nitroglycerine Musculoskeletal Chest Pain - UA = no history of trauma and lack of response to nitroglycerine

Question 30

Are ECGs always abnormal in a patient with unstable angina?

Answer 30

- No May be normal, BUT common presentations include: - ST-segment changes - T wave inversion - new bundle branch block

Question 31

Which of the following scoring systems is used to help guide the severity of the acute coronary syndrome and guide management? 1 - CURB65 2 - WELLS2 3 - CHA2DS2-VASc 4 - GRACE

Answer 31

4 - GRACE Takes into account age, vital signs, kidney function, cardiac markers among others.

Question 32

GRACE score helps guide the management of patients with acute coronary syndrome. Patients with a score above what would be considered for Coronary Angiography, which may lead to percutaneous coronary intervention? 1 - >1% 2 - >3% 3 - >10% 4 - >20%

Answer 32

2 - >3% >3% = moderate to high risk of 6-month probability of death <3% = low risk of 6-month probability of death

Question 33

If a patient presents with symptoms of acute coronary syndrome (ACS) we must perform the following as soon as possible: - bloods (troponin) - ECG - risk scoring (GRACE score) In addition, patients should be treated with which 4 of the following? 1 - aspirin 300mg 2 - IV morphine 3 - nitrates 4 - enoxaparin 5 - oxygen

Answer 33

1 - aspirin 300mg 2 - IV morphine 3 - nitrates (GTN spray) 5 - oxygen GTN is a vasodilator and can cause a drop in BP and syncope Fondaparinux may be given as an anti-thrombin therapy if required, but only for NSTEMI and unstable angina

Question 34

If a patient presents with acute coronary syndrome and has a GRACE score >3%, how soon should they have angiography, with a potential follow up for percutaneous coronary intervention? 1 - >12h 2 - <72h 3 - <7 days 4 - >14 days

Answer 34

2 - <72h

Question 35

Following the initial presentation, a patient will be advised about lifestyle changes. They will also be placed on all of the following medications as part of secondary prevention, EXCEPT which one? 1 - Bisoprolol 2 - Doxazosin 3 - Dual anti-platelet therapy (aspirin and ticagrelor) 4 - Atorvastain 5 - Ramipril

Answer 35

2 - Doxazosin This is an alpha blocker and not indicated Swap ticagrelor for clopidogrel if patient has a high bleeding risk. ACE and B-blocker should be titrated up to maximum doses within 4-6 weeks

Question 36

Before starting an ACE and after 1-2 weeks, all of the following should be monitored, EXCEPT which one? 1 - eGFR 2 - U&Es 3 - LFTS 4 - Blood pressure

Answer 36

3 - LFTS

Question 37

How long are patients with acute coronary syndrome advised to take dual anti-platelet therapy for before it needs to be reviewed? 1 - 4 weeks 2 - 12 weeks 3 - 12 months 4 - Lifelong

Answer 37

3 - 12 months

Question 38

Which 2 of the following are the most likely complications of unstable angina? 1 - chronic heart failure 2 - superior vena cava obstruction 3 - MI 4 - arrhythmias

Answer 38

3 - MI 4 - arrhythmias - VT and VF may occur